Question

I want to remove the last entry in my array, and I want the array to show me that it has 1 less entry when I am using the ${#array[@]}. This is the current line I am using:

unset GreppedURLs[${#GreppedURLs[@]} -1]

Please correct me and show me the right way.

Answer 1

The answer you have is (nearly) correct for non-sparse indexed arrays¹:

unset 'arr[${#arr[@]}-1]'

Bash 4.3 or higher added this new syntax to do the same:

 unset arr[-1]

(Note the single quotes: they prevent pathname expansion).

Demo:

arr=( a b c )
echo ${#arr[@]}

3

for a in "${arr[@]}"; do echo "$a"; done

a
b
c

unset 'arr[${#arr[@]}-1]'
for a in "${arr[@]}"; do echo "$a"; done

a
b

Punchline

echo ${#arr[@]}

2

(GNU bash, version 4.2.8(1)-release (x86_64-pc-linux-gnu))

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¹ @Wil provided an excellent answer that works for all kinds of arrays