近期在学python,得益于python中的decorator思路，想到在javascript中參数是不能定义默认值的，可是能够通过decorator给它模拟出来，话不多说，上代码
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title></title>
</head>
<body>
<script type="text/javascript">
function defaultArg(params, fun) {
function f() {
var args = [];
for (i = 0; i < arguments.length || i < params.length; i++) {
if (i >= arguments.length || arguments[i] == null) {
args.push(params[i]);
}
else {
args.push(arguments[i]);
}
}
fun.apply(this, args);
}
return f;
}
function ClassA() {
this.name = "ClassA";
}
ClassA.prototype.show = defaultArg(
//尽管有点另类，但非常像decorator吧
["default1","default2"],
function (arg1,arg2) {
alert("[" + this.name + "]" + arg1 + "," + arg2);
});
var inst = new ClassA();
inst.show(); //这里将使用默认參数
inst.show("hello");
inst.show("hello","world");
</script>
</body>
</html>