Exact string search in array

Question

I have an array like:

moduleList=(AB, ABCdef, ABCd)

My array is numerically-indexed array not an associative array. I want to do an exact match for each element in array and to perform certain tasks.

Currently I'm doing like:

if [[  ${moduleList["AB"]}  ]]; then
    #do this.
fi



if [[  ${moduleList["ABCdef"]}  ]]; then
    #do that.
fi

But both the conditions are getting true as "AB" is there in each word. How can I distinguish each condition based on an exact match.

Answer 1

${moduleList["AB"]} or the same without the quotes takes the value of a variable called AB, and uses that as the index. If that variable is not set, the value you get is zero, and that expands to AB, the zeroth item of the array. That's a non-empty string, so it's truthy.

But both the conditions are getting true as "AB" is there in each word.

This, quite simply, is not the reason. You'd get the same with ${moduleList["x"]}, or whatever. Or, if the named variable is set to a number, you get the appropriate item in the array:

$ moduleList=(AB, ABCdef, ABCd)
$ unset x
$ echo "${moduleList[x]}"
AB,
$ x=2
$ echo ${moduleList["x"]}
ABCd

You'll have to loop over the array to find if a matching string exists, or change into an associative array and use the strings in as keys.

Also note that you probably don't want the commas in the assignment, you get literal commas in the values, as seen above.