check if variable is array, returns 0 on success, 1 otherwise

is_array.bash

# check if variable is array, returns 0 on success, 1 otherwise
# @param mixed 

is_array()
{   #detect if arg is an array, returns 0 on sucess, 1 otherwise
    [ -z "$1" ] && return 1
    if [ -n "$BASH" ]; then
        declare -p ${1} 2> /dev/null | grep 'declare \-a' >/dev/null && return 0
    fi
    return 1
}