Quick 'n dirty interview question #2

find-palindromes.js

/**
 *  Given a list of words, write a function that returns only those
 *  words which are palindromes (written the same forwards and
 *  backwards).
 * 
 * Ex.
 * 
 * var list = ['racecar', 'balloon', 'moon', 'history'];
 * findPalindromes(list) == ['racecar', 'moon'];
 */
var list = [
  'racecar',
  'sledgehammer',
  'potato',
  'kayak',
  'rotator',
  'renaissance'
];

function findPalindromes(list) {
  
  var result = []
    , i = 0
    , len = list.length;

  for (i; i < len; i++) {
    
    // There are lots of ways to do this, but the basic idea
    // is that you need to compare the string to the reverse
    // of the string.
    if (list[i].toLowerCase() === list[i].split('').reverse().join('').toLowerCase()) {
      result.push(list[i]);
    }
  }

  return result;
}