SOURCE

String.prototype.format = function() {
    var args = arguments;
    return this.replace(/\{(\d+)\}/g,
    function(m, i) {
        return args[i];
    });
}

var testString = "<p>此次更新内容：</p>{0}<p>是否现在更新？</p>";
console.log(testString.format("1.我是测试的</br>2.是否是测试的"));