Question

I constructed a function defined as

var Func1 = function() 
{
    return {
             alert: function() { alert( "Lady Gaga" ); }
           };
};

And I assigned Func1() to a variable, like this:

var func1 = Func1();

I found something make no sense to me that Func1() created an object for func1 although I didn’t put the new in front of it.

Isn’t that objects could only be created by new?

What happened when the expression above is being executed?

Answer 1

When you write a javascript literal object (json like), it’s the equivalent to create a new object with the new operator and assign its properties.

This

var a = { test: 123, caca: 'pipi' };

Is the same as

var a = new Object();

a.test = 123;
a.caca = 'pipi';