我有一个这样的数组:
var arr1 = ["a", "b", "c", "d"];
我如何随机化/打乱它?
我有一个这样的数组:
var arr1 = ["a", "b", "c", "d"];
我如何随机化/打乱它?
当前回答
或者像上面所有的答案,但简而言之。
function shuffle(a) { for (var c, d, b = a.length; 0 !== b;)d = Math.floor(Math.random() * b), b -= 1, c = a[b], a[b] = a[d], a[d] = c; return a }
其他回答
使用underscore.js库。对于这种情况,方法_.shuffle()很好。以下是该方法的示例:
var _ = require("underscore");
var arr = [1,2,3,4,5,6];
// Testing _.shuffle
var testShuffle = function () {
var indexOne = 0;
var stObj = {
'0': 0,
'1': 1,
'2': 2,
'3': 3,
'4': 4,
'5': 5
};
for (var i = 0; i < 1000; i++) {
arr = _.shuffle(arr);
indexOne = _.indexOf(arr, 1);
stObj[indexOne] ++;
}
console.log(stObj);
};
testShuffle();
添加到@Laurens Holsts的答案。这是50%的压缩。
function shuffleArray(d) {
for (var c = d.length - 1; c > 0; c--) {
var b = Math.floor(Math.random() * (c + 1));
var a = d[c];
d[c] = d[b];
d[b] = a;
}
return d
};
var shuffledArray = function(inpArr){
//inpArr - is input array
var arrRand = []; //this will give shuffled array
var arrTempInd = []; // to store shuffled indexes
var max = inpArr.length;
var min = 0;
var tempInd;
var i = 0;
do{
//generate random index between range
tempInd = Math.floor(Math.random() * (max - min));
//check if index is already available in array to avoid repetition
if(arrTempInd.indexOf(tempInd)<0){
//push character at random index
arrRand[i] = inpArr[tempInd];
//push random indexes
arrTempInd.push(tempInd);
i++;
}
}
// check if random array length is equal to input array length
while(arrTempInd.length < max){
return arrRand; // this will return shuffled Array
}
};
只需将数组传递给函数,然后得到经过洗牌的数组
这里有简单的while循环
function ShuffleColor(originalArray) {
let shuffeledNumbers = [];
while (shuffeledNumbers.length <= originalArray.length) {
for (let _ of originalArray) {
const randomNumb = Math.floor(Math.random() * originalArray.length);
if (!shuffeledNumbers.includes(originalArray[randomNumb])) {
shuffeledNumbers.push(originalArray[randomNumb]);
}
}
if (shuffeledNumbers.length === originalArray.length)
break;
}
return shuffeledNumbers;
}
const colors = [
'#000000',
'#2B8EAD',
'#333333',
'#6F98A8',
'#BFBFBF',
'#2F454E'
]
ShuffleColor(colors)
虽然已经建议了许多实现,但我觉得我们可以使用forEach循环使其更短、更容易,因此我们不必担心计算数组长度,也可以安全地避免使用临时变量。
var myArr = ["a", "b", "c", "d"];
myArr.forEach((val, key) => {
randomIndex = Math.ceil(Math.random()*(key + 1));
myArr[key] = myArr[randomIndex];
myArr[randomIndex] = val;
});
// see the values
console.log('Shuffled Array: ', myArr)