About call and apply those things

1. Definition:

Call: Invokes one method of an object, replacing the current object with another object.

Apply: A method of applying an object that replaces the current object with another object.

2. Usage:

Call:call (Thisobj, arg1, arg2, ...); Description: Thisobj typically represents an object, and if the Thisobj parameter is not provided, the Global object will act as thisobj. The second argument begins, such as arg1 ... Arbitrary form parameters can be passed.

Apply:apply (Thisobj, [Argarray]); Description: Thisobj typically represents an object, and if the Thisobj parameter is not provided, the Global object will act as thisobj. The second argument must start with an array or arguments.

3. Difference:

The difference is in the second argument.

4. Personal Understanding:

In fact, the method of the previous object is applied to the latter object (the first parameter in parentheses). That is, it changes the pointer to this.

5, do not say anything, on a few simple code:

1             functionfunc1 (name) {2                  This. Name =name;3                  This. ShowName =function(){4Console.log ( This. Name);5                 }6             }7 8             functionFunc2 (name) {9                  This. name=name;Ten             } One  A             varObj1 =NewFunc1 ("Func1"); -             varObj2 =NewFunc2 ("Func2"); - obj1.showname (); theObj2.showname ();//Direct error, because there is no ShowName () method in Obj2 -Obj1.showName.call (OBJ2);//This allows the ShowName () method in the Obj1 to be used for OBJ2

6. To implement inheritance

1             functionfunc1 (name) {2                  This. Name =name;3                  This. ShowName =function(){4Console.log ( This. Name);5                 }6             }7 8             functionFunc2 (name) {9Func1.call ( This, name);Ten             } One  A             varObj2 =NewFunc2 ("Func2"); -Obj2.showname ();

About call and apply those things