Question

Is there a way of checking if a string exists in an array of strings – without iterating through the array?

For example, given the script below, how I can correctly implement it to test if the value stored in variable $test exists in $array?

array=('hello' 'world' 'my' 'name' 'is' 'perseus')

#pseudo code
$test='henry'
if [$array[$test]]
   then
      do something
   else
      something else
fi

Note

I am using bash 4.1.5

Answer 1

With bash 4, the closest thing you can do is use associative arrays.

declare -A map
for name in hello world my name is perseus; do
  map["$name"]=1
done

…which does the exact same thing as:

declare -A map=( [hello]=1 [my]=1 [name]=1 [is]=1 [perseus]=1 )

…followed by:

tgt=henry
if [[ ${map["$tgt"]} ]] ; then
  : found
fi