随机偏移数组值

Question

If I have

var numbs = [1, 2, 3, 4]

var new numbs = [1 + Math.random() * 2 - 1, 2 + '' , 3 + etc....

So I end up with something like:

var new numbs = [.877, 2.166, 2.456, 4.235] 

There has to be a better way to do this...

Answer 1

// This gives you an array with 4 items all collected using Math.random()
var nums = Array.apply(null, Array(4)).map(function(v, key) {
    return Math.round(Math.random() * 100) / 100;
});
nums; // [0.64, 0.35, 0.36, 0.44]

You can then use key (the index) in your calculation:

// This gives you an array with 4 items all collected using Math.random()
var nums = Array.apply(null, Array(4)).map(function(v, key) {
    return key + Math.round(Math.random() * 100) / 100;
});
nums; // [0.36, 1.52, 2.35, 3.89]

---

var nums = Array.apply(null, Array(4)).map(function(){});

is basically the same as writing:

var nums = [];
for ( var i = 0; i < 4; i++ ) {
     nums.push( /*something*/ );
} 

But you will get a closed scope.

Answer 2

Math.random（）基本上用于生成0到1之间的随机十进制数。因此，如果您对获取整数元素感兴趣，请使用Math.floor（Math.random（））或Math.ceil（Math.random（））或Math.round（Math.random（））根据您的要求。

Answer 3

You could do something like this using Array.prototype.map

Javascript

function randomBetween(min, max) {
    return Math.random() * (max - min) + min;
}

var numbs = [1, 2, 3, 4],
    numbsOffset = numbs.map(function (value) {
        return +(value + randomBetween(-1, 1)).toFixed(2);
    });

console.log(numbsOffset);

On jsfiddle

Or you can use a for loop if you don't want to use ECMAScript 5