从 JavaScript 数组中获取随机项
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/5915096/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Get random item from JavaScript array
提问by James
var items = Array(523,3452,334,31,...5346);
How do I get random item from items?
我如何从 中获得随机物品items？
回答by Kelly
var item = items[Math.floor(Math.random() * items.length)];
回答by Alnitak
If you really mustuse jQuery to solve this problem (NB: you shouldn't):
如果你真的必须使用 jQuery 来解决这个问题（注意：你不应该）：
(function($) {
$.rand = function(arg) {
if ($.isArray(arg)) {
return arg[$.rand(arg.length)];
} else if (typeof arg === "number") {
return Math.floor(Math.random() * arg);
} else {
return 4; // chosen by fair dice roll
}
};
})(jQuery);
var items = [523, 3452, 334, 31, ..., 5346];
var item = jQuery.rand(items);
This plugin will return a random element if given an array, or a value from [0 .. n) given a number, or given anything else, a guaranteed random value!
如果给定一个数组，或者给定一个数字，或者给定其他任何东西，一个来自 [0 .. n) 的值，这个插件将返回一个随机元素，一个有保证的随机值！
For extra fun, the array return is generated by calling the function recursively based on the array's length :)
为了更有趣，通过基于数组的长度递归调用函数来生成数组返回:)
Working demo at http://jsfiddle.net/2eyQX/
回答by chim
Use underscore (or loDash :)):
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)];
Or to shuffle an entire array:
或者打乱整个数组：
// use underscore's shuffle function
var firstRandomElement = _.shuffle(randomArray)[0];
回答by Dino Reic
1. solution: define Array prototype
1.解决方案：定义Array原型
Array.prototype.random = function () {
return this[Math.floor((Math.random()*this.length))];
}
that will work on inline arrays
这将适用于内联数组
[2,3,5].random()
and of course predefined arrays
当然还有预定义的数组
list = [2,3,5]
list.random()
2. solution: define custom function that accepts list and returns element
2.解决方案：定义接受列表并返回元素的自定义函数
get_random = function (list) {
return list[Math.floor((Math.random()*list.length))];
}
get_random([2,3,5])
回答by K-Gun
Here's yet another way:
这是另一种方式：
function rand(items) {
return items[~~(items.length * Math.random())];
}
回答by Rocket Hazmat
var random = items[Math.floor(Math.random()*items.length)]
回答by planetjones
jQuery is JavaScript! It's just a JavaScript framework. So to find a random item, just use plain old JavaScript, for example,
jQuery 就是 JavaScript！它只是一个 JavaScript 框架。因此，要查找随机项目，只需使用普通的旧 JavaScript，例如，
var randomItem = items[Math.floor(Math.random()*items.length)]
回答by Blindy
var rndval=items[Math.floor(Math.random()*items.length)];
回答by Ivan
// 1. Random shuffle items
items.sort(function() {return 0.5 - Math.random()})
// 2. Get first item
var item = items[0]
Shorter:
更短：
var item = items.sort(function() {return 0.5 - Math.random()})[0];
回答by neebz
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];
credit:
信用：
