Manejando Listas, Mapas y más cosas con underscorejs

He visto por ahí esta librería de JavaScript y lo comparto con todos.

http://underscorejs.org/

Ejemplo de esta librería:

   _.each([1, 2, 3], function(num, i) {
      equal(num, i + 1, 'each iterators provide value and iteration count');
    });

    var answers = [];
    _.each([1, 2, 3], function(num){ answers.push(num * this.multiplier);}, {multiplier : 5});
    equal(answers.join(', '), '5, 10, 15', 'context object property accessed');

    answers = [];
    _.forEach([1, 2, 3], function(num){ answers.push(num); });
    equal(answers.join(', '), '1, 2, 3', 'aliased as "forEach"');

    answers = [];
    var obj = {one : 1, two : 2, three : 3};
    obj.constructor.prototype.four = 4;
    _.each(obj, function(value, key){ answers.push(key); });
    equal(answers.join(", "), 'one, two, three', 'iterating over objects works, and ignores the object prototype.');
    delete obj.constructor.prototype.four;

    var answer = null;
    _.each([1, 2, 3], function(num, index, arr){ if (_.include(arr, num)) answer = true; });
    ok(answer, 'can reference the original collection from inside the iterator');

    answers = 0;
    _.each(null, function(){ ++answers; });
    equal(answers, 0, 'handles a null properly');

 Recursos:

• GitHub del proyecto: enlace.