finding common prefix of array of strings

Question

I have an array like this:

$sports = array(
\'Softball - Counties\',
\'Softball - Eastern\',
\'Softball - North Harbour\',
\'Softball - South\',
\'Softball -         


        

Answer 1

Here's an elegant, recursive implementation in JavaScript:

function prefix(strings) {
    switch (strings.length) {

      case 0:
        return "";

      case 1:
        return strings[0];

      case 2:
        // compute the prefix between the two strings
        var a = strings[0],
            b = strings[1],
            n = Math.min(a.length, b.length),
            i = 0;
        while (i < n && a.charAt(i) === b.charAt(i))
            ++i;
        return a.substring(0, i);

      default:
        // return the common prefix of the first string,
        // and the common prefix of the rest of the strings
        return prefix([ strings[0], prefix(strings.slice(1)) ]);
    }
}