# 如何改组数组？[重复]

2020/09/25 12:40 · javascript ·  · 0评论

[0, 3, 3] -> [3, 0, 3]
[9, 3, 6, 0, 6] -> [0, 3, 6, 9, 6]
[3, 3, 6, 0, 6] -> [0, 3, 6, 3, 6]

/**
* Shuffles array in place.
* @param {Array} a items An array containing the items.
*/
function shuffle(a) {
var j, x, i;
for (i = a.length - 1; i > 0; i--) {
j = Math.floor(Math.random() * (i + 1));
x = a[i];
a[i] = a[j];
a[j] = x;
}
return a;
}

## ES2015（ES6）版本

/**
* Shuffles array in place. ES6 version
* @param {Array} a items An array containing the items.
*/
function shuffle(a) {
for (let i = a.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[a[i], a[j]] = [a[j], a[i]];
}
return a;
}

## 用

var myArray = ['1','2','3','4','5','6','7','8','9'];
shuffle(myArray);

## 实施原型

Object.defineProperty(Array.prototype, 'shuffle', {
value: function() {
for (let i = this.length - 1; i > 0; i--) {
const j = Math.floor(Math.random() * (i + 1));
[this[i], this[j]] = [this[j], this[i]];
}
return this;
}
});

function shuffle(array) {
let counter = array.length;

// While there are elements in the array
while (counter > 0) {
// Pick a random index
let index = Math.floor(Math.random() * counter);

// Decrease counter by 1
counter--;

// And swap the last element with it
let temp = array[counter];
array[counter] = array[index];
array[index] = temp;
}

return array;
}