Question

How can I remove a sub-string (a prefix) from a array of string elements? (remove the sub string from each element)

Answer 1

Using RegExp and ^ to ensure it is the prefix and not just somewhere in the string:

var arr = ['a1', 'a2', 'a54a'];
for(var i = 0, len = arr.length; i < len; i++) {
    arr[i] = arr[i].replace(/^a/, '');
}
arr; // '1,2,54a' removing the 'a' at the begining