You have two ways to create a new array in bash … name is any name for an array; index could be any number or expression that must evaluate to a number greater than or equal to zero.You can declare an explicit array using declare -a arrayname. Also, initialize an array, add an element, update element and delete an element in the bash script. Declaring an Array and Assigning values. You can also do for i in "${!array[@]}" to directly get the array indices, which will handle missing indices and associative arrays without problems. This tutorial will help you to create an Array in bash script. Check if Two Strings are Equal # In most cases, when comparing strings you would want to check whether the strings are equal or not. The Bash provides one-dimensional array variables. An array in BASH is like an array in any other programming language. 1. Bash does not segregate variables by “type”, variables are treated as integer or string depending on the context. Create a bash file named ‘for_list4.sh’ and add the following script.In this example, every element of the array variable, StringArray contains values of two words. An array is a variable that can hold multiple values, where each value has a reference index known as a key. Arrays are indexed using integers and are zero-based. array=( H E L L O ) # you don’t even need quotes array[0] $ = H. if you wanted to accept other ascii chars (say you’re converting to hex for some reason) array=(H E L L O “#” “!” ) #some chars you’ll want to use the quotes. Any variable may be used as an array; the declare builtin will explicitly declare an array. I have this line comming from STDIN : (5,[a,b,c,d,e,f,g,h,i,j]) The five is my group ID and the letters are values of an array (the group data). Each array element is accessible via a key index number. There is no maximum limit on the size of an array, nor any requirement that members be indexed or assigned contiguously. In bash, array is created automatically when a variable is used in the format like, name[index]=value. To print each value without splitting and solve the problem of previous example, you just need to enclose the array variable with double quotation within for loop. In BASH script it is possible to create type types of array, an indexed array or associative array. Example-4: Print multiple words string value as a single value. 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. allThreads = (1 2 4 8 16 32 64 128). Create indexed arrays on the fly – muru Dec 13 '17 at 5:17 add a comment | 0 Define An Array in Bash. awk Associative Array and/or Referring to Field by String (Nonconstant String Value) I will start with an example of what I'm trying to do and then describe how I am approaching the issue. If your input string is already separated by spaces, bash will automatically put it into an array: ex. I already read How to split a string into an array in bash but the question seems a little different to me so I'll ask using my data. In this example, all the elements are numbers, but it need not be the case—arrays in Bash can contain both numbers and strings, e.g., myArray=(1 2 "three" 4 "five") is a valid expression. The first thing we'll do is define an array containing the values of the --threads parameter that we want to test:. Bash arrays are indexed arrays by default: An indexed array is created automatically if any variable is assigned to using the syntax name[subscript]=value ... 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