var items = Array(523, 3452, 334, 31, ..., 5346);

我如何从项目中获得随机项目?


当前回答

const ArrayRandomModule = {
  // get random item from array
  random: function (array) {
    return array[Math.random() * array.length | 0];
  },

  // [mutate]: extract from given array a random item
  pick: function (array, i) {
    return array.splice(i >= 0 ? i : Math.random() * array.length | 0, 1)[0];
  },

  // [mutate]: shuffle the given array
  shuffle: function (array) {
    for (var i = array.length; i > 0; --i)
      array.push(array.splice(Math.random() * i | 0, 1)[0]);
    return array;
  }
}

其他回答

var items = Array(523,3452,334,31,...5346);

function rand(min, max) {
  var offset = min;
  var range = (max - min) + 1;

  var randomNumber = Math.floor( Math.random() * range) + offset;
  return randomNumber;
}


randomNumber = rand(0, items.length - 1);

randomItem = items[randomNumber];

信贷:

Javascript函数:随机数生成器

使用下划线(或loDash:)):

var randomArray = [
   '#cc0000','#00cc00', '#0000cc'
];

// use _.sample
var randomElement = _.sample(randomArray);

// manually use _.random
var randomElement = randomArray[_.random(randomArray.length-1)];

或者洗牌整个数组:

// use underscore's shuffle function
var firstRandomElement = _.shuffle(randomArray)[0];
var item = items[Math.floor(Math.random()*items.length)];
const ArrayRandomModule = {
  // get random item from array
  random: function (array) {
    return array[Math.random() * array.length | 0];
  },

  // [mutate]: extract from given array a random item
  pick: function (array, i) {
    return array.splice(i >= 0 ? i : Math.random() * array.length | 0, 1)[0];
  },

  // [mutate]: shuffle the given array
  shuffle: function (array) {
    for (var i = array.length; i > 0; --i)
      array.push(array.splice(Math.random() * i | 0, 1)[0]);
    return array;
  }
}

还有另一种方法:

function rand(items) {
    // "~~" for a closest "int"
    return items[~~(items.length * Math.random())];
}

或者按照下面@1248177的建议:

function rand(items) {
    // "|" for a kinda "int div"
    return items[items.length * Math.random() | 0];
}