It only works with a 1-element array of an empty string, not 2 elements. Arrays in Bash. Bash Associative Arrays by Mitch Frazier. 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). Using unset() Function: The unset() function is used to remove element from the array. array=${array[@]:1} #removed the 1st … An associative array lets you create lists of key and value pairs, instead of just numbered values. Deleting Array Elements. When setting associative array values and a duplicate assignment occurs, bash overwrites the key. You can assign values to arbitrary keys: $ I have no idea why you have two counters. on April 28, 2010. When you remove one from the array, you should decrement the counter. Let's see an example: There are the associative arrays and integer-indexed arrays. To access array elements, we use array_name[index] format. I guess I didn't test that comment before posting. Elements in arrays are frequently referred to by their index number, which is the position in which they reside in the array. Remove duplicate array elements. Dictionary / associative arrays / hash map are very useful data structures and they can be created in bash. 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. The unset function is used to destroy any other variable and same way use to delete any element of an array. I normally use ksh instead of bash (and it has had associative arrays since 1993). Unfortunately, bash and ksh declare associative arrays 6.7 Arrays. So "if condition then incremement counter, else remove item at current position" Last edited by Trilby (2012-09-06 11:51:32) These index numbers are always integer numbers which start at 0. Bash provides one-dimensional indexed and associative array variables. Similarly, we can use delete statement to remove an element from the array. In Bash, there are two types of arrays. I avoided associative arrays in my suggestion, because I only have access to bash version 3.2.57(1)-release (x86_64-apple-darwin16) and it doesn't have associative arrays. For insertion, we used assignment operator. They work quite similar as in python (and other languages, of course with fewer features :)). unset array[0] removes the element but still if I do echo ${array[0]} I get a null value moreover there are other ways of doing this but if an element of an array contains spaces like below array[0]='james young' array[1]='mary' array[2]='randy orton' but these also fail to do the job. There is no maximum limit on the size of an array, nor any requirement that members be indexed or assigned contiguously. Alternately, only increment the counter in the conditional code for when you dont remove and item. Deleting an element from the array To delete an element from the array we need to know it's index or its key in the case of an associative array, and use the unset command. Introduction to bash arrays and bash array operations. The syntax of delete statement is as follows − Syntax delete array_name[index] The following example deletes the element orange. This unset command takes the array key as input and removed that element from the array. Bash, however, includes the ability to create associative arrays, and it treats these arrays the same as any other array. I even checked older bash and it's still wrong there; like you say set -x shows how it expands. To check the version of bash run following: It should iterate over each defined name and run the command. We will go over a few examples. Example Function: This allows us to effectively remove array duplicates. CAVEAT: Requires bash 4+ CAVEAT: List order may not stay the same. 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