JavaScript handler construct() Method

by Online Tutorials Library July 22, 2022

JavaScript handler.construct() Method

The handler.construct() method is used to intercept the new operation. This method returns an object.

Syntax

Parameters

Target: The target object.

argumentsList: List of the constructor.

newTarget: The constructor that was originally called, p above.

Return value

This method returns an object.

Browser Support

Chrome	49
Edge	12
Firefox	18
Opera	36

Example 1

  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);  

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Output:

Java Script proxy Constructor

Example 2

  var pro = new Proxy(function()                      {}, {    construct: function(objTarget, args, oldConstructor) {       return { Value : args[0] + ” to anybody” }    }  })    document.write(JSON.stringify(new pro(“Hello “), null, ‘ ‘))  

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Output:

{ "Value": "Hello to anybody" }

Example 3

  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);  

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Output:

Constructor called Proxi

Next TopicJavaScript handler

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JavaScript handler construct() Method

JavaScript handler.construct() Method

Syntax

Parameters

Return value

Browser Support

Example 1

Example 2

Example 3

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