<!DOCTYPE html>
<html>
<head>
<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.js"></script>
</head>
<body>
<script>
var Single = (function () {
var instance = null;
var defaultData = {age: 25};
SingleInstance.prototype._init = function (ops) {
for (var a in defaultData) {
this[a] = defaultData[a];
}
for (var b in ops) {
this[b] = ops[b];
}
};
function SingleInstance(args) {
if (this instanceof SingleInstance) {
if (instance == null) {
instance = this;
}
instance._init(args);
return instance;
}else {
if(instance==null){
instance=new SingleInstance;
}
instance._init(args);
return instance;
}
}
return SingleInstance;
})();
var i1 = new Single({name: "xu"});
var i2 = new Single({name: "tong"});
var i3 = Single({name: "bao"});
console.log(i1 === i2); //true
console.log(i1 === i3); //true
console.log(i1.name); //bao
console.log(i1.age); //25
</script>
</body>
</html>
