The method handler.construct serves to intercept the creation of new instances. This function yields an object as its output.
Syntax
Example
construct: function(target, argumentsList, newTarget)
Parameters
Target : The target object.
argumentsList : List of the constructor.
newTarget: The constructor that was initially invoked, represented by p above.
Return value
This method returns an object.
Browser Support
| Chrome | 49 |
|---|---|
Edge |
12 |
| Firefox | 18 |
| Opera | 36 |
Example 1
Example
var B= function(text) {
this.text = text;
};
var Button1 = new Proxy(B, {
construct: function(target, parameters) {
document.writeln('Java Script');
var button= Object.create(target.prototype);
target.apply(button, parameters);
return button;
}
});
var button = new Button1('proxy Constructor');
document.writeln(button.text);
Output:
Output
Java Script proxy Constructor
Example 2
Example
var pro = new Proxy(function()
{}, {
construct: function(objTarget, args, oldConstructor) {
return { Value : args[0] + " to anybody" }
}
})
document.write(JSON.stringify(new pro("Hello "), null, ' '))
Output:
Output
{ "Value": "Hello to anybody" }
Example 3
Example
function M(val) {
this.val = val;
}
const N = {
construct(target, args) {
document.writeln('Constructor called');
return new target(...args);
}
};
const proxy= new Proxy(M, N)
document.writeln(new proxy('Proxi').val);
Output:
Output
Constructor called Proxi
