Check if a Bash array contains a value

Question

In Bash, what is the simplest way to test if an array contains a certain value?

Answer 1

The following code checks if a given value is in the array and returns its zero-based offset:

A=("one" "two" "three four")
VALUE="two"

if [[ "$(declare -p A)" =~ '['([0-9]+)']="'$VALUE'"' ]];then
  echo "Found $VALUE at offset ${BASH_REMATCH[1]}"
else
  echo "Couldn't find $VALUE"
fi

The match is done on the complete values, therefore setting VALUE="three" would not match.