Function sample

docs/_static/underscore-1.13.1.js:1520–1536

(obj, n, guard)

  // If **n** is not specified, returns a single random element.
  // The internal `guard` argument allows it to work with `_.map`.
  function sample(obj, n, guard) {
    if (n == null || guard) {
      if (!isArrayLike(obj)) obj = values(obj);
      return obj[random(obj.length - 1)];
    }
    var sample = isArrayLike(obj) ? clone(obj) : values(obj);
    var length = getLength(sample);
    n = Math.max(Math.min(n, length), 0);
    var last = length - 1;
    for (var index = 0; index < n; index++) {
      var rand = random(index, last);
      var temp = sample[index];
      sample[index] = sample[rand];
      sample[rand] = temp;
    }
    return sample.slice(0, n);
  }

  // Shuffle a collection.
  function shuffle(obj) {