JS比较两个字符串不同的部分标红显示

function StringBuffer() {
    this.__strings__ = [];
};
StringBuffer.prototype.append = function (str) {
    this.__strings__.push(str);
    return this;
};
//格式化字符串
StringBuffer.prototype.appendFormat = function (str) {
    for (var i = 1; i < arguments.length; i++) {
        var parent = "\\{" + (i - 1) + "\\}";
        var reg = new RegExp(parent, "g")
        str = str.replace(reg, arguments[i]);
    }

    this.__strings__.push(str);
    return this;
}
StringBuffer.prototype.toString = function () {
    return this.__strings__.join('');
};
StringBuffer.prototype.clear = function () {
    this.__strings__ = [];
}
StringBuffer.prototype.size = function () {
    return this.__strings__.length;
}

/*
    * 传入2个字符串进行相比高亮显示
    * 例如
    * 原数据一:王五张三
    * 原数据二:张三李四
    * 王五张三
    * 张三李四
    
    * 例如
    * 原数据一:1000
    * 原数据二:10012
    * 1000
    * 10012
    html里下边调用
    
    
    
*/

var flag = 1;

function getHighLightDifferent(a, b) {
    //console.log("输入：" + a);
    //console.log("输入：" + b);

    var temp = getDiffArray(a, b);
    var a1 = getHighLight(a, temp[0]);
    //console.log("输出：" + a1);

    var a2 = getHighLight(b, temp[1]);
    //console.log("输出：" + a2);
    //console.log(flag);
    return new Array(a1,a2);
}

function getHighLight(source, temp) {
    var result = new StringBuffer();
    var sourceChars = source.split("");
    var tempChars = temp.split("");
    var flag = false;
    for (var i = 0; i < sourceChars.length; i++) {
        if (tempChars[i] != ' ') {
            if (i == 0) {
                result.append("");
                result.append(sourceChars[i]);
            }
            else if (flag) {
                result.append(sourceChars[i]);
            }
            else {
                result.append("");
                result.append(sourceChars[i]);
            }
            flag = true;
            if (i == sourceChars.length - 1) {
                result.append("");
            }
        }
        else if (flag == true) {
            result.append("");
            result.append(sourceChars[i]);
            flag = false;
        } else {
            result.append(sourceChars[i]);
        }
    }
    return result.toString();
}

function getDiffArray(a, b) {
    var result = new Array();
    //选取长度较小的字符串用来穷举子串
    if (a.length < b.length) {
        var start = 0;
        var end = a.length;
        result = getDiff(a, b, start, end);
    } else {
        var start = 0;
        var end = b.length;
        result = getDiff(b, a, 0, b.length);
        result = new Array(result[1], result[0]);
    }
    return result;

}

//将a的指定部分与b进行比较生成比对结果
function getDiff(a, b, start, end) {
    var result = new Array(a, b);
    var len = result[0].length;
    while (len > 0) {
        for (var i = start; i < end - len + 1; i++) {
            var sub = result[0].substring(i, i + len);
            var idx = -1;
            if ((idx = result[1].indexOf(sub)) != -1) {
                result[0] = setEmpty(result[0], i, i + len);
                result[1] = setEmpty(result[1], idx, idx + len);
                if (i > 0) {
                    //递归获取空白区域左边差异
                    result = getDiff(result[0], result[1], start, i);
                }
                if (i + len < end) {
                    //递归获取空白区域右边差异
                    result = getDiff(result[0], result[1], i + len, end);
                }
                len = 0;//退出while循环
                break;
            }
        }
        len = parseInt(len / 2);
        //len = len - 1;
        //console.log(len);
    }
   //console.log(result.join(""));
    return result;
}

//将字符串s指定的区域设置成空格
function setEmpty(s, start, end) {
    var array = s.split("");
    for (var i = start; i < end; i++) {
        array[i] = ' ';
    }
    return array.join("");
}