Sequential Search (js)

sequential_search.js

(function() {
  var sequential = function(haystack, needle) {
    var i = 0,
      len = haystack.length
      ;

    for (; i < len; i++) {
      if (haystack[i] === needle) {
        return true;
      }
    }

    return false;
  };
})();

sequential_search_v2.js

(function() {
  var sequential_v1 = function(haystack, needle) {
    return haystack.filter(function(element) {
        return element === needle
      }).length > 0;
  };
})();

sequential_search_v3.js

(function() {
  var search = function(haystack, needle) {
    var l = haystack.length;
    while (haystack[--l] !== needle);
    return l > -1;
  }
})();