The most intuitive way to understand the difference between javascript constructors and ordinary functions

The way to distinguish a javascript function from a constructor or an ordinary function is to see which calling method they use. Whether a javascript constructor or a javascript ordinary function is a function, they are always functions. Their calling method determines whether they are constructors or ordinary functions.

The following is the declaration of a function, which is a function, but the way it is used later determines whether it is a constructor or a normal function:

 function website(name,url){ this.webName = name; this.webUrl = url; }

Constructor

 Var site=new website ("resource sharing"“ http://www.aiyuanma.org/ "); site.webName; //Resource sharing site.webUrl;  // http://www.aiyuanma.org/

Call this function through the new operator, and this function is used as a constructor. That is, any function can be used as a constructor.

Ordinary function

 Website ("resource sharing"“ http://www.aiyuanma.org/ "); window.webName; //Resource sharing window.webUrl;  //  http://www.aiyuanma.org/

This function is used as a normal function. This points to the window object. That is to say, any function can be regarded as a normal function.

Summary:

1. The difference between them is so simple. The new operator is used as a constructor, and other methods are used as ordinary functions;

2. Any javascript function can be used as a constructor or a normal function