js根据属性动态生成getter、setter方法

Object.prototype.setProperties = function(properties){

var obj = this;

// Iterate through the properties of the object, and make sure
// that it's properly scoped (as discussed previously)
for ( var i in properties ) {
(function(j){
// Create a new getter for the property
obj[ "get" + j ] = function() {
return properties[j];
};

// Create a new setter for the property
obj[ "set" + j ] = function(val) {
properties[j] = val;
};
})(i);
}
}

// Create a new user object that accepts an object of properties
function User( properties ) {
this.setProperties(properties);
}

// Create a new user object instance and pass in an object of
// properties to seed it with
var user = new User({
name: "Bob",
age: 44
});

// Just note that the name property does not exist, as it's private
// within the properties object
alert( user.name == null );

// However, we're able to access its value using the new getname()
// method, that was dynamically generated
alert( "name:" + user.getname() + ",age:" + user.getage());

// Finally, we can see that it''s possible to set and get the age using
// the newly generated functions
user.setage( 22 );
alert( user.getage() == 22 );