How can I expand the variable inside this sed expression? [duplicate]

Question

I have a text file like this:

melon = [2 2 4 5];
apple = [3 6 4 4];
lemon = [1 5 4 8];

And I want to make a function that reads a named variable into a bash array. This is what I came up with - that doesn't work since the variable $FruitToParse doesn't get expanded:

#!/bin/bash
set -e
set -u

function file_to_array {
    local FileToParse=${1}
    local FruitToParse=${2}

    for i in `cat ${FileToParse} | sed -n -e 's/.*${FruitToParse} = \[\(.*\)\];/\1/p'`); do
        echo ${i}
    done    
}

file_to_array fruits.txt apple

Answer 1

use double quotes on sed instead of single quotes;

$ bob="cool"; echo "bob is sad" | sed "s/sad/$bob/"
bob is cool