复制代码 代码如下:

var oldtime = new Date().getTime();

var str = [];

for(i=0;i<100000;i++)

{

str.push('abcabcabcabcabcabcabcabcabcabcabcabc');

}

var newtime = new Date().getTime();

var joinTime = (newtime - oldtime);

var oldtime = new Date().getTime();

var str='';

for(i=0;i<100000;i++)

{

str += 'abcabcabcabcabcabcabcabcabcabcabcabc';

}

var newtime = new Date().getTime();

var concatTime = (newtime - oldtime);

alert("join / concat: " + (joinTime * 1.0 / concatTime));

注：循环次数必须足够大。