The behavior of new when creating an object with a constructor

Create an object with a constructor:
var obj=new typename(property value,...)
new: 4 things:
1. Create an empty object
2. Let the new child object inherit the constructor's prototype object settings (automatically set the new object's The __proto__ property points to the prototype object of the constructor)
3. Call the constructor: 　　1. this->new 　　2. this.property name=value: Add a new property to the object by force assignment, and save the property value 4. Returns the address of the new object, stored in a variable