| while read line; \ unset MYMAP[$K] This might help: https://www.gnu.org/software/gawk/manual/gawk.html. >declare -p item For the benefit of future visitors to this page (like me) that are running pre-4.2 bash, the comment in your statement: “$ MYMAP[foo]=bar # Or this line implicitly makes it an associative array (in global scope)”. Numerically indexed arrays can be accessed from the end using negative indices, the index of -1references the last element. echo “a apple” > /tmp/fruit #!/bin/bash do \ Furthermore, if the values of $item1 and $item2 were not integers (strings), the values would go back to being implicitly 0 again. Really useful, I was stuck declaring an associative implicitly inside a function, apparently you need declare -A for that to work fine. The case is quite different if you have defined values for $item1 and $item2: >item1=12 1838. However, any regular (non-special or positional) parameter may be validly referenced using a subscript, because in most contexts, referring to the zeroth element of an array is synonymous with referring to the array name without a subscript. Bash, however, includes the ability to create associative arrays, and it treats these arrays the same as any other array. unset MYMAP[‘$K’]. So in order to do what you want, the while loop needs to be in the process with the rest of the script. Associative arrays can be used when the data is organized by a string, for example, host names. unset MYMAP[“$K”], However, this one does work: for i in "${!fruit[@]}"; do One of these commands will set replication servers. Hi Matteo, thanks – yes those would be useful. Some are satisfied with converting a list to a string and calling it a day, but if you truly want to deal with an official bash array, the here sting above will do that for you. fruit[a] = ‘apple’; fruit[p]=pumpkin. I am writing a bash script on CentOS 7.5 that will execute some MongoDB commands. readarray will create an array where each element of the array is a line in the input. 3 years ago. two. As you can guess it was not the first time I saw it, but in an article like this, people will copy it, as you can also see in the comments above. Now, I have my task cut out. K=’ ‘ Copyright (C) 2013 Free Software Foundation, Inc. How to concatenate string variables in Bash. Play lots of games online, and learn how to make your own. >echo ${item[24]} fruit[p] = 'pumpkin', Can you please explain why do you add “+_” when you trying to test value existing? >declare -p item The indices do not have to be contiguous. Any variable may be used as an array; the declare builtin will explicitly declare an array. I am totally confused, it works, it inits and declares, it’s simple you can see the values but well… it’s like an awk 1 to me??? Hope that helped (someone) this font is so small i can hardly read it for some reason today, so if i made a mistake that’s why ( too lazy to zoom :) ) <- double chin! Also, if K is a single or double quote, only the latter one works! a loop is an overhead. echo "fruit[$i] = '${fruit[$i]}'" $ bash test.sh echo “c cranberry” >> /tmp/fruit, declare -A fruit Passing to a function and how to assign between variables (both arrays) is missing IMHO. Answered all my questions at once. Simple, neat, to the point. 1731. fruit[b]= sorex[“FR”] I normally create an indexed array from the sql query result as below: I’m confused about scope. echo “a apple” > /tmp/fruit bash-4.1$ keys=( ${!ARY[@]} ) FRUITS, while read t f; do The best solution probably is, as already been pointed out, to iterate through the array and copy it step by step. I found the rest of the article quite good, so it was a disappointment to see this tip at the end. Wow, just have learned how to use associative arrays, via this very handy page! bash-4.1$, Hi CPRitter, that looks like a pretty good way to do this, but I think at this point I’d be reaching for Perl or Python…. for i in ${!f[@]}; do $2 “$i” “${f[$i]}”; done Bash associative arrays are supported in bash version 4. for (i in sorex) print i }’, Hi Mark, that code inside the single quotes is all Awk code, not bash. fruit[a] = 'apple' fruit[$t]="$f" I just tried declare -A MYMAP here and it worked. Read a file (data stream, variable) line-by-line (and/or field-by-field)? See below for accessing the different properties of an array. The second command will remove the array. done < /tmp/fruit, echo "" The former are arrays in which the keys are ordered integers, while the latter are arrays in which the keys are represented by strings. Except I can’t see the syntax in any manual or search I’ve done. done. How to check if a variable is set in Bash? This site uses Akismet to reduce spam. $ /tmp/t.bash Indexed arrays are accessed the same way as “Hashes”. Your email address will not be published. Bas… fruit[c]= Awesome, thank you Self-Perfection – I have fixed it. However, I find that things like: $ declare -A foo[“flap”]=”three four” foo[“flop”]=”one two” Writing about Bash is challenging because it's remarkably easy for an article to devolve into a manual that focuses on syntax oddities 2962. in the above example, if the variables $item1 and $item2 are un[define]d, then the result would be: this happened because undeclared variables have an implicit value of 0 when used as an indexer, it would be so these two lines are identical: >item=( [item1]=”one” [item2]=”two ) echo 1 | awk ‘{ sorex[“W”] zibble: zabble If you agree with that, then you probably won't want to read about the "new" associative arrays that were added in version 4.0 of bash. x=2 Don't subscribe This is important because many programmers expect that because integer arrays are implicit, that the associative arrays _should be_ too. The following first command will print all values of the array named assArray1 in a single line if the array exists. An associative array can be declared in bash by using the declare keyword and the array elements can be initialized at the time of array declaration or after declaring the array variable. unset MYMAP[‘ ‘] A common use is for counting occurrences of some strings. Bash Associative Array (dictionaries, hash table, or key/value pair) You cannot create an associative array on the fly in Bash. 3> Create an assoc array from the result of sql query. $ foreach foo bar How to iterate over associative arrays in Bash. This is free software; you are free to change and redistribute it. They work quite similar as in python (and other languages, of course with fewer features :)). Explains everything about associative arrays in a single article. Amazing! You can initialize elements one at a time as follows: aa[hello]=world aa[ab]=cd aa["key with space"]="hello world" Bash & ksh: if [[ -v "MYARRAY[key5]" ]] ; then # code if key exist else # code if key does not exist fi Test if the value for a key is an empty string. if done on a un[define]d variable, will treat it like an -a instead of an -A, which causes the last entry only to be recognized as the first indexer (zero) unless, of course, those items have value. You can assign values to arbitrary keys: $ Bash provides one-dimensional indexed and associative array variables. To check the version of bash run following: There is no maximum limit on the size of an array, nor any requirement that members be indexed or assigned contiguously. 1. In those cases, hopefully the habit of doing it in scripts rubs off on you enough to have it done in the interactive ones as well :). Hi Dave, if you set a variable value inside the do .. done it does not leak out of the scope: $ cat /tmp/t.bash a apple Here is a quick start tutorial for using bash associative arrays. You can also subscribe without commenting. :-). The best solution probably is, as already been pointed out, to iterate through the array and copy it step by step. Sorry you can’t use it! Before use associative array needs to be declared as shown below: The first one is to use declare command to define an Array. 1> how to convert a nornal array (indexed array with index starting at 0) into an associative array where value becomes a key and value itself is the value. You can and should use. Hi Craig, thanks for the very informative addition. Default variable test/expansion rules apply: $ declare -A ax; done. How do I set a variable to the output of a command in Bash? The Bash provides one-dimensional array variables. Copying associative arrays is not directly possible in bash. Using "trap" to react to signals and system events. Thanks Will, updated. n o bbl e: nibble echo $x. echo “b banana” >> /tmp/fruit *//’); \ See below for accessing the different properties of an array. Loop through an array of strings in Bash? How to use 'readarray' in bash to read lines from a file into a 2D , This is the expected behavior. It differentiates between the case where a key does not exist, and the case where it does exist but its value is null. Any variable may be used as an indexed array; the declare builtin will explicitly declare an array. SET Andy: Create indexed arrays on the fly 2> Create a new assoc array from indexed array where values are keys. Define An Array in Bash. You could use the same technique for copying associative arrays: Associative arrays are like traditional arrays except they uses strings as their indexes rather than numbers. echo “fruit[$t] = ‘${fruit[${t}]}’; fruit[p]=${fruit[p]}.” ; \ Bash provides one-dimensional indexed and associative array variables. Cell. * //’); \ dictionaries were added in bash version 4.0 and above. Indexed arrays are accessed the same way as “Hashes”. co bb le: cribble c cranberry Associative array in Bash – Linux Hint, Any associative array can be removed by using `unset` command. Bash & ksh: If not pre-declared, then your example (if NOT preceded by "declare -A"): implicitly performs arithmetic evaluation of the expression "foo", which produces a numeric result of "0", thereby assigning element "0" of *indexed* array "MYMAP". echo "fruit[$t] = '${fruit[${t}]}'; fruit[p]=${fruit[p]}." yes, Nice Way to show examples. And it even appears that way if the array was [declare]d one previously. Smolpxl. So far, you have used a limited number of variables in your bash script, you have created few variables to hold one or two filenames and usernames.. You can now use full-featured associative arrays. Avi, are you sure you are using bash? You can create an array that contains both strings and numbers. And what I also especially like about it, is that along with examples how to do things, it also gives the examples how to NOT do certain things. As a RULE, it is good to just declare ALL variables. item=([0]=”two”), >item=( [0]=”one” [0]=”two ) Note: bash version 4 only. $ echo ${ax[bar]:-MISSING}; Bash & ksh: echo ${#MYARRAY[@]} Test if a key exist. fruit[c] = 'cranberry' fruit[c] = ‘cranberry’; fruit[p]=pumpkin. Now, I was brought to your site while searching for a solution to this …, Is there a less clumsy method of sorting keys than this (spaces in keys must be preserverd)…, bash-4.1$ declare -A ARY=( [fribble]=frabble [grabble]=gribble [co bb le]=cribble [babble]=bibble [zibble]=zabble [n o bbl e]=nibble [mobble]=mibble ) Thank you very much for such a priceless post. I’m jealous of this. A tiny programming language designed to demonstrate how to write a language (Python) FreeGuide. And it apparently stays in local scope too. Bash supports both regular arrays that use integers as the array index, and associative arrays, which use a string as the array index. A few Bourne-like shells support associative arrays: ksh93 (since 1993), zsh (since 1998), bash (since 2009), though with some differences in behaviour between the 3. Required fields are marked *. item=([0]=”two”). Use this higher order function to prevent the pyramid of doom: foreach(){ Your email address will not be published. A TV guide program that downloads programme info … Bash Array – An array is a collection of elements. Of course, if you had already had values in the other index 0, it would have been erased by this though not touching index 0 you are still resetting the value of the variable — unless you used += instead of =. The third command is used to check the array … All An associative array lets you create lists of key and value pairs, instead of just numbered values. At present, I’m struggling to find solution to either of the following problems: echo “fruit[b]=${fruit[‘b’]}” Get the length of an associative array. echo “fruit[a]=${fruit[‘a’]}” b banana no, # if [ ${MYMAP[blablabla]+_} ]; then echo yes; else echo no;fi Re Missing Keys and the “+_” in the examples: this is in fact quite important, and it’s a good thing you quoted it in this guide. fruit[p]=pumpkin Bash readarray. #!/bin/bash The label may be different, but whether called “map”, “dictionary”, or “associative array… There are the associative arrays and integer-indexed arrays. Unlike most of the programming languages, arrays in bash scripting need not be the collection of similar elements. one Before use associative array needs to be declared as shown below: declare -A hash hash=(["k1"]="v1" ["k2"]="v2") And this in a single statement. Bash supports one-dimensional numerically indexed and associative arrays types. So, instead you can do: cat >/tmp/fruit <echo ${item[12]} Hashes in Bash. Learn how your comment data is processed. This is necessary, because otherwise bash doesn't know what kind of array you're trying to make. The following doesn’t work as I expect. The bash man page has long had the following bug listed: "It's too big and too slow" (at the very bottom of the man page). $ echo ${ax[foo]:+SET}; mobble: mibble A clear HowTo. xkcd >item2=24 fruit[$t]=$f ; \ There is NO WARRANTY, to the extent permitted by law. If you want to see the whole Per the Bash Reference Manual, Bash provides one-dimensional indexed and associative array variables. :) I just bashed (cough) my head against the keyboard for 10 minutes because I’m on bash 3.2.8 (OSX 10.7.5). bash-4.1$ IFS=$’\n’ sorted_keys=( $( echo -e “${keys[@]/%/\n}” | sed -r -e ‘s/^ *//’ -e ‘/^$/d’ | sort ) ) You’re only checking the version of the bash which is found first in your path, not necessarily the one you’re currently running. fruit[b] = 'banana' Associative arrays (aka hashes) can be used since Bash v4 and need a declaration like this There is another solution which I used to pass variables to functions. array[wow]: command not found An associative array is an array which uses strings as indices instead of integers. where $DB_NAME is the variable pointing to DB name string. t=$(echo $line|sed -e ‘s/ . fruit[b] = 'banana'; fruit[p]=pumpkin. Stackoverflow: How to iterate over associative array in bash; Share on Mastodon Posted on October 17, 2012 July 10, 2020 Author Andy Balaam Categories bash, Programming Languages, Tech Tags associative-arrays, bash, maps, quoting, variable-expansion. f=$(echo $line|sed -e ‘s/. san francisco. declare: usage: declare [-afFirtx] [-p] [name[=value] …], using the quotes around the values throws an error like this: Great site… but I am looking for an explanation of the code below? Since Bash 4 was released, there is no longer any excuse to use indirection (or worse, eval) for this purpose. $ bash –version This command will define an associative array named test_array. unset MYMAP[ ] There is no maximum limit on the size of an array, nor any requirement that members be indexed or assigned contiguously. But what if you need more than few variables in your bash scripts; let’s say you want to create a bash script that reads a hundred different input from a user, are you going to create 100 variables? License GPLv3+: GNU GPL version 3 or later. According to project, number of servers can be different. You have two ways to create a new array in bash script. Thanks again. Maybe, but in these attention dearth times formulating in sharply pointed way is often the only way to get people notice and remember. Associative array are a bit newer, having arrived with the version of Bash … Bash supports both regular arrays that use integers as the array index, and associative arrays, which use a string as the array index. otherwise keys with spaces would split to separate array items. Create an array The first thing to do is to distinguish between bash indexed array and bash associative array. $ echo ${ax[foo]:-MISSING}; Any variable may be used as an indexed array; the declare builtin will explicitly declare an array. fruit[c] = 'cranberry'; fruit[p]=pumpkin. is not true for bash versions <4.2 wherein associative arrays MUST be explicitly created with "declare -A". The following script will create an associative array named assArray1 and the four array values are initialized individually. We will go over a few examples. An array is a Bash parameter that has been given the -a (for indexed) or -A (for associative) attributes. I have this associative array that is the hostname an IPs of servers (I used an associative array because other parts of code needed it). Since bash does not discriminate string from a number, an array can contain a mix of strings and numbers. It doesn’t work because you are piping the output of `cat /tmp/fruit` into a while loop, but the second command in the pipe (the while loop) spawns in a new process. flop -> one two. I make it a habit to use “shopt -o -s nounset” in my scripts. declare -a test_array In another way, you can simply create Array by assigning elements. flap -> three four echo “fruit[c]=${fruit[‘c’]}” The problem with such tips is that they will give the right answer most of the time, leading to even more confusion and frustration when they don’t. When using an associative array, you can mimic traditional array by using numeric string as index. Accessing array elements in bash The first element of an array starts at index 0 and so to access the nth element of array you use the n -1 index. I used to do a lot of bash+cmdline-perl (perl -e) to do what a simple ass.array in bash could have done. declare -a MYMAP='([0]="bar")'. declare -A aa Declaring an associative array before initialization or use is mandatory. In this article, we will explain how you can declare and initialize associative arrays in Linux bash. Bash Array. Declare and initialize associative array. Bash: Associative array initialization and usage Just as in other programming languages, associative arrays in Bash are useful for search, set management, and keying into a list of values. fruit[a]= It works for me without this addition: Using GNU bash, version 4.2.25(1)-release (x86_64-pc-linux-gnu). You can initialize elements one at a time as follows: You can also initialize an entire associative array in a single statement: Iterate over associative array keys and values, This modified text is an extract of the original Stack Overflow Documentation created by following, getopts : smart positional-parameter parsing. Hot Network Questions fruit[b] = ‘banana’; fruit[p]=pumpkin. Bash return an associative array from a function and then pass that associative array to other functionsHelpful? babble: bibble It’s been a L.O.N.G time since I went to the net for ‘just bash’ questions (:=), so it was great to hear that bash now has ass.arrays. In order to get the scope to work how you expect, @Dave, you need to invert the operations. In this topic, we will demonstrate the basics of bash array and how they are used in bash shell scripting. Here is a quick start tutorial for using bash associative arrays. Thanks a million for the page and examples. Copying associative arrays is not directly possible in bash. $ ax[foo]=”xkcd”; fruit[a] = 'apple'; fruit[p]=pumpkin. bash-4.1$ for key in “${sorted_keys[@]}”; do echo “$key: ${ARY[$key]}”; done GNU bash, version 4.3.11(1)-release (x86_64-pc-linux-gnu) Then these do not work: Declaring an associative array before initialization or use is mandatory. A command to print a summary of your git branches (Bash). As you can see on the second line, the index ‘0’ gets defined twice, of course the last being the final value for that index. You can only use the declare built-in command with the uppercase “-A” option.The += operator allows you to append one or multiple key/value to an associative Bash array. Replies to my comments I wish I had found it before I spent an hour figuring it out myself. Numerical arrays are referenced using integers, and associative are referenced using strings. Regular arrays should be used when the data is organized numerically, for example, a set of successive iterations. Other examples of Array Basics Shell Script: KEYS=(${!MYMAP[@]}). /home/ubuntu# if [ ${MYMAP[blablabla]} ]; then echo yes; else echo no;fi. Also, array indexes are typically integer, like array[1],array[2] etc., Awk Associative Array. Is there any reason this must be performed on an in-memory array? Elements in arrays are frequently referred to by their index number, which is the position in which they reside in the array. Awk supports only associative array. grabble: gribble You can assign values to arbitrary keys: $ declare: -A: invalid option However, interactive scripts like .bashrc or completion scripts do not always have this luxury, because it’s a pain to set it, and then unset it, also saving the value which is overhead in the sense of time taken to implement/reimplement each time. These index numbers are always integer numbers which start at 0. unset MYMAP[” “] There is another solution which I used to pass variables to functions. Associative arrays are an abstract data type similar to dictionaries or maps. There is no maximum limit on the size of an array, nor any requirement that members be indexed or assigned contiguously. An associative array lets you create lists of key and value pairs, instead of just numbered values. So in that subprocess, the variables are being set, but when the while loop terminates the subprocess terminates and the changes to the variables are lost. For example, to print the value of the 2 nd element of your files array, you can use the following echo statement : Thanks for the write up but would you consider wrapping “bash version 4 only” at the start of the article in strong tags? Bash, however, includes the ability to create associative arrays, and it treats these arrays the same as any other array. Associative arrays (aka hashes) can be used since Bash v4 and need a declaration like this 6.7 Arrays. I know it can very well be done using a loop but for a huge sized array containing almost 500,000 elements, fruit[p]=pumpkin Arrays to the rescue! >item=( [item1]=”one” [item2]=”two ), > declare -p item Dictionary / associative arrays / hash map are very useful data structures and they can be created in bash. MISSING $ cat /tmp/t.bash 1. Arrays are indexed using integers and are zero-based. Associative arrays can be created in the same way: the only thing we need to change is the option used: instead of lowercase -a we must use the -A option of the declare command: $ declare -A my_array This, as already said, it's the only way to create associative arrays in bash. To create an associative array, you need to declare it as such (using declare -A). Bash & ksh: Hi Sharon, I don’t actually know why I added +_ – I am wondering whether this is an artefact of copying and pasting from somewhere else… Thanks for the comment! $ declare -p MYMAP }, $ bar(){ echo “$1 -> $2”; } There is an error in “Numeric indexing” section $. You could use the same technique for copying associative … Get the length of an associative array. Bash, however, includes the ability to create associative arrays, and it treats these arrays the same as any other array. 47 thoughts on “Bash associative array … Bash & ksh: if [[ -v "MYARRAY[key5]" ]] ; then # code if key exist else # code if key does not exist fi Test if the value for a key is an empty string. If you are familiar with Perl, C, or Java, you might think that Bash would use commas to separate array elements, however this is not the case; instead, Bash uses spaces: # Array in Perl my @array = (1, 2, 3, 4); Bash supports both regular arrays that use integers as the array index, and associative arrays, which use a string as the array index. The way you have written the examples is just as one developer talks to another.. To use Sharon’s example, this indeed seems to work: # if [ ${MYMAP[blablabla]} ]; then echo yes; else echo no;fi Unlike most of the programming languages, Bash array elements don’t have to be of the same data type. Notify me of followup comments via e-mail. Bash, however, includes the ability to create associative arrays, and it treats these arrays the same as any other array. We will further elaborate on the power of the associative arrays with the help of various examples. This solution does not pass an array from a function, but it does allow you to convert the output of a function to an array. Unlike in many other programming languages, in bash, an array is not a collection of similar elements. Bash version bash associative array and above a quick start tutorial for using bash associative arrays, and associative are referenced strings. Of your git branches ( bash ) following doesn ’ t have to of... You Self-Perfection – I have fixed it, number of servers can be removed by using numeric string index. P ] =pumpkin a disappointment to see the whole Per the bash Reference Manual, bash array an. Not a collection of similar elements, of course with fewer features: ) ) assArray1 and the case a. How they are used in bash script am looking for an explanation of the article good. Reason this must be performed on an in-memory array ’ ) ; \ f= $ ( echo $ -e! The way to check if a variable key from an associative array in bash hour figuring it out myself free! Declare an array ; the declare builtin will explicitly declare an array bash scripting need not be the of. Examples is just as one developer talks to another latter one works language designed to demonstrate how assign. Another way, you can simply create array by assigning elements all Replies to my comments Notify me of comments... Array and copy it step by step 're trying to make index number, an array, any... Variables ( both arrays ) is missing IMHO make your own work how you can create array. Implicitly inside a function and how to use declare command to print a summary of your current?! Programming languages, bash array – an array is a quick start tutorial for using associative... Array from indexed array where values are initialized individually MYMAP declare -A.! Can declare and initialize associative arrays, via this very handy page in. ( both arrays ) is missing IMHO Linux Hint, any associative array variables used! Command is used to do what you want, the while loop to. Are free to change and redistribute it t work as I expect of numbered! I have fixed it should be used since bash does n't know what kind of array you 're trying make. Make your own my scripts to other functionsHelpful … indexed arrays are accessed the same way as “ Hashes.. It worked return an associative array before initialization or use is for counting of! Split to separate array items strings and numbers organized numerically, for example, host.. Basics of bash array elements bash associative array ’ t see the syntax in any Manual or search ’... * // ’ ) ; \ f= $ ( echo $ line|sed -e ‘ s/ named in... Nounset ” in my scripts on the size of an associative array where... Ksh: echo $ line|sed -e ‘ s/ Jason Bache, used under CC-BY-2.0 error in numeric... / associative arrays in bash the input script will create an array can contain a of! For example, a set of successive iterations the operations in any Manual or search I ’ ve.. Discovered about how to use 'readarray ' in bash script I had found it before I spent hour. Arrays ) is missing IMHO `` 0 '', not the string `` foo '' you are free change... ‘ banana ’ ; fruit [ a ] = 'cranberry ' ; fruit [ ]! Copying associative arrays, and it treats these arrays the same technique for associative. Work how you can simply create array by using ` unset ` command very much such... That variable may be a single or double quote, only the latter one!. Or maps `` trap '' to react to signals and system events does exist but its value null... Return an associative array, you can create an array that contains both strings numbers. The following first command will define an array can be defined as a collection of similar of. What kind of array you 're trying to make I discovered about how to between!, bash provides one-dimensional array variables like array [ 2 ] etc. Awk! Will define an array c ] = ‘ cranberry ’ ; fruit [ a ] = 'cranberry ;. Used since bash v4 and need a declaration like this 6.7 arrays ” in scripts! Yes those would be useful error in “ numeric indexing ” section example KEYS= ( $ #! For that to work how you expect, @ Dave, you need to declare it as such using. -A '' of just numbered values, thank you very much for such a priceless.... ( [ 0 ] = 'cranberry ' ; fruit [ p ] =pumpkin to delete a variable set. Implicitly inside a function and how they are used in bash could have done, a set of successive.. A set of successive iterations `` 0 '', not the string `` foo '' supports one-dimensional numerically indexed can. Can create an array frequently referred to by their index number, an array array items work quite similar in. Both arrays ) is missing IMHO elements don ’ t work as I expect ; the declare builtin will declare. Banana ’ ; fruit [ b ] = 'cranberry ' ; fruit [ p ].! Of just numbered values, for example, host names ; \ f= $ ( echo $ line|sed -e s/! The declare builtin will explicitly declare an array which uses strings as indices instead of just values. It treats these arrays the same as any other array, number of can... String `` foo '' you have two ways to create associative arrays ( aka Hashes ) can defined! Explains everything about associative arrays is not true for bash versions < 4.2 associative... Only the latter one works array lets you create lists of key value. Bash shell scripting 're trying to make your own a disappointment to see this tip at the.. Indices, the index of -1references the last element have learned how to write a language Python! Indexes are typically integer, like array [ 2 ] etc., Awk associative array variables of I! Declare all variables assign values to arbitrary keys: $ indexed arrays are accessed the same as any other.! And associative arrays must be performed on an in-memory array be of the code below print! Of various examples solution probably is, as already been pointed out, to iterate the... Not exist, and learn how to assign between variables ( both arrays ) is missing IMHO below for the! I just tried declare -A MYMAP here and it even appears that if. Of array you 're trying to make are keys: bash associative array can contain mix!