JavaScript 字符串处理函数

//截取字符串 包含中文处理
function SubString(str, len, hasDot) {
    var newLength = 0;
    var newStr = "";
    var chineseRegex = /[^\x00-\xff]/g;
    var singleChar = "";
    var strLength = str.replace(chineseRegex, "**").length;
    for (var i = 0; i < strLength; i++) {
        singleChar = str.charAt(i).toString();
        if (singleChar.match(chineseRegex) != null) {
            newLength += 2;
        }
        else {
            newLength++;
        }
        if (newLength > len) {
            break;
        }
        newStr += singleChar;
    }

    if (hasDot && strLength > len) {
        newStr += "...";
    }
    return newStr;
}

//字符串连接
function StringBuffer() {
    this._string = new Array;
}

StringBuffer.prototype.append = function(str) {
    return this._string.push(str);
}

StringBuffer.prototype.toString = function() {
    return this._string.join("");
}