温故知新——JavaScript中的字符串连接问题最全总结（推荐）

var str = "hello ";
str += "world";

var arr = new Array();
arr[0] = "hello ";
arr[1] = "world";
var str = arr.join("");

function StringBuffer () {
 this._strings_ = new Array();
}
StringBuffer.prototype.append = function(str) {
 this._strings_.push(str);
};
StringBuffer.prototype.toString = function() {
 return this._strings_.join("");
};

var buffer = new StringBuffer ();
buffer.append("hello ");
buffer.append("world");
var result = buffer.toString();

var d1 = new Date();
var str = "";
for (var i=0; i < 10000; i++) {
 str += "text";
}
var d2 = new Date();
document.write("Concatenation with plus: "
 + (d2.getTime() - d1.getTime()) + " milliseconds");
var buffer = new StringBuffer();
d1 = new Date();
for (var i=0; i < 10000; i++) {
 buffer.append("text");
}
var result = buffer.toString();
d2 = new Date();
document.write("<br />Concatenation with StringBuffer: "
 + (d2.getTime() - d1.getTime()) + " milliseconds");