考虑:
var myArray = ['January', 'February', 'March'];
如何使用JavaScript从这个数组中选择一个随机值?
当前回答
Randojs使这更简单和可读:
console.log(rando(['January'， 'February'， 'March'])。值); < script src = " https://randojs.com/1.0.0.js " > < /脚本>
其他回答
我找到了一种方法来解决顶部答案的复杂性，只需将变量rand连接到另一个变量，允许该数字在myArray[];的调用中显示。通过删除创建的新数组并处理它的复杂性，我提出了一个可行的解决方案:
<!DOCTYPE html>
<html>
<body>
<p id="demo"></p>
<script>
var myArray = ['January', 'February', 'March', 'April', 'May'];
var rand = Math.floor(Math.random() * myArray.length);
var concat = myArray[rand];
function random() {
document.getElementById("demo").innerHTML = (concat);
}
</script>
<button onClick="random();">
Working Random Array generator
</button>
</body>
</html>
最短的版本: var myArray = ['January'， 'February'， 'March']; var rand = myArray[(Math.random() * myArray.length) | 0] console.log (rand)
创建一个随机值并传递给数组
请尝试以下代码..
//For Search textbox random value
var myPlaceHolderArray = ['Hotels in New York...', 'Hotels in San Francisco...', 'Hotels Near Disney World...', 'Hotels in Atlanta...'];
var rand = Math.floor(Math.random() * myPlaceHolderArray.length);
var Placeholdervalue = myPlaceHolderArray[rand];
alert(Placeholdervalue);
假设你想随机选择一件与上次不同的物品(不是真的随机，但仍然是一个常见的要求)……
/**
* Return a random element from an array that is
* different than `last` (as long as the array has > 1 items).
* Return null if the array is empty.
*/
function getRandomDifferent(arr, last = undefined) {
if (arr.length === 0) {
return null;
} else if (arr.length === 1) {
return arr[0];
} else {
let num = 0;
do {
num = Math.floor(Math.random() * arr.length);
} while (arr[num] === last);
return arr[num];
}
}
实现如下:
const arr = [1,2,3];
const r1 = getRandomDifferent(arr);
const r2 = getRandomDifferent(arr, r1); // r2 is different than r1.
这与@Jacob Relkin的解决方案类似，但更普遍:
这是ES2015:
const randomChoice = arr => {
const randIndex = Math.floor(Math.random() * arr.length);
return arr[randIndex];
};
该代码的工作原理是在0到数组长度之间选择一个随机数，然后返回该下标处的项。
