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随机产生去重数组

2015-03-26 18:00:15| 分类： JS | 标签： |举报 |字号大中小订阅

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今天看到同事的一段代码如下：

var result = [];
for(var j = 0; j < 10; j++) {
    result[j] = Math.round( Math.random() * 100 );
    if(j > 0) {
        for(var m = j - 1; m >= 0; m--) {
            if(result[j] == result[m]) {
                j--;
                break;
            }
        }
    }
}

代码中for循环和if语句嵌套的层次太多，如果不是随机取10个数，而是取更多的数的话，这样for循环的次数太多了，代码执行的时间也会变长。所以思考使用空间换时间的方式，来简化代码，并且减少语句的嵌套，代码如下：

var result = [];
var temp = [];
var len = 0;
var num;
while(len < 10){
    num = Math.round( Math.random() * 100 );
    if(!temp[num]) {
        temp[num] = 1;
        result.push(num);
        len++;
    }
}

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