JS字符串累加Array不一定比字符串累加快(根据电脑配置)

<script type="text/javascript">
function StringBuffer() {
this._strings = new Array();
}
StringBuffer.prototype.append = function(str) {
this._strings.push(str);
//StringBuffer.prototype.length = this._strings.length;//每多一行，就会多消耗处理时间
var i = "asdfasdf";
}
StringBuffer.prototype.toString = function() {
this._strings.join("");
}
/*String类 + 号累加*/
var d = new Date();//累加开始时间
var str = "1";
for (var i = 0; i < 200; i++) {
str += "ssss";
for (var i = 0; i < 30000; i++) {
str += "text";
}
}
var d2 = new Date(); //累加结束时间
document.write("+："+(d2.getTime() - d.getTime()) + "milliseconds");//累加30000用时
/*自定义StringBuffer类 字符串累加*/
d = new Date(); //StringBuffer开始时间
var buffer = new StringBuffer();
for (var i = 0; i < 200; i++) {
str += "ssss";
for (var i = 0; i < 30000; i++) {
buffer.append("text");
}
}
var resultstr = buffer.toString();
d2 = new Date();
document.write("<br/>StringBuffer：" + (d2.getTime() - d.getTime()) + "milliseconds");
/*直接使用Array 不进行封装*/
d = new Date();
var arr = new Array();
for (var i = 0; i < 200; i++) {
str += "ssss";
for (var i = 0; i < 30000; i++) {
arr.push("text");
}
}
var resStr = arr.join("");
d2 = new Date();
document.write("<br/>Array：" + (d2.getTime() - d.getTime()) + "milliseconds");
</script>
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