The handler.defineProperty function serves the purpose of establishing new properties. Additionally, it enables direct alterations of existing properties on an object. This function acts as a trap for Object.defineProperty. It can be utilized in two specific scenarios.
- When it is necessary to guarantee cross-browser compatibility for getters and setters.
- Whenever there is a need to create a custom property accessor.
Syntax
Example
defineProperty: function(target, property, descriptor)
Parameters
Target : The target object.
Property : Retrieved property description.
Descriptor: The characteristic that is being specified or altered.
Return value
This method returns a Boolean
Browser Support
| Chrome | 49 |
|---|---|
Edge |
12 |
| Firefox | 18 |
| Opera | 36 |
Example 1
Example
var target = {}
target.foo = 'bar'
document.writeln(Object.getOwnPropertyDescriptor(target, 'foo'))
Output:
Output
[object Object]
Example 2
Example
var xyz = {};
var proxy = new Proxy(xyz, {
defineProperty: function(target, name, propertyDescriptor) {
document.writeln('in defineProperty');
return Object.defineProperty(target, name, propertyDescriptor);
}
});
Object.defineProperty(proxy, 'bar', {} );
Output:
Output
in defineProperty
Example 3
Example
var xyz ={};
var hu = {};
var proxy = new Proxy(xyz, {
defineProperty: function(target, name, propertyDescriptor) {
document.writeln('Learn Java Script');
return Object.defineProperty(target, name, propertyDescriptor);
}
});
var pro= new Proxy(hu, {
defineProperty: function(target, name, propertyDescriptor) {
document.writeln('Proxt Method ');
return Object.defineProperty(target, name, propertyDescriptor);
}
});
Object.defineProperty(proxy, 'bar', {} );
Object.defineProperty(pro, 'hug', {} );
Output:
Output
Learn Java Script Proxt Method
