js随机从数组中取出几个元素javascript
假如数组为
var items = ['1','2','4','5','6','7','8','9','10'];
1.从数组items中随机取出一个元素
var item = items[Math.floor(Math.random()*items.length)];
2.从前面的一篇随机数组中随机取几个元素
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假如数组为
var items = ['1','2','4','5','6','7','8','9','10'];
1.从数组items中随机取出一个元素
var item = items[Math.floor(Math.random()*items.length)];
2.从前面的一篇随机数组中随机取几个元素
function getRandomArrayElements(arr, count) {
var shuffled = arr.slice(0), i = arr.length, min = i - count, temp, index;
while (i-- > min) {
index = Math.floor((i + 1) * Math.random());
temp = shuffled[index];
shuffled[index] = shuffled[i];
shuffled[i] = temp;
}
return shuffled.slice(min);
}
var items = ['1','2','4','5','6','7','8','9','10'];
console.log( getRandomArrayElements(items, 4) );
var items = ['1','2','4','5','6','7','8','9','10'];
1.从数组items中随机取出一个元素
var item = items[Math.floor(Math.random()*items.length)];
2.从前面的一篇随机数组中随机取几个元素
function getRandomArrayElements(arr, count) {
var shuffled = arr.slice(0), i = arr.length, min = i - count, temp, index;
while (i-- > min) {
index = Math.floor((i + 1) * Math.random());
temp = shuffled[index];
shuffled[index] = shuffled[i];
shuffled[i] = temp;
}
return shuffled.slice(min);
}
var items = ['1','2','4','5','6','7','8','9','10'];
console.log( getRandomArrayElements(items, 4) );
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