Call function and apply function

One, Function.call () function

1, A.call (b)??; include 3rd [pass. Call (b) before object to B object]//much like inheritance

Pass the A object (all) to the B function object????;

2, A.amethod.call (b)?; Does not overwrite the same name method in B

Pass the Amethod method of? A to the B function object;

3. The test code is as follows:

2. function A (NAMEA) {
4. This.name=namea;
6. This.showname=function () {
8. return this.name;
10. }
12. }
14. function B (NAMEB) {
16. A.call (THIS,NAMEB);
18. This.showtest=function () {
20. return NAMEB;
22. }
24. Duplicate Name method
26. This.showname=function () {
28. return "Soul";
30. //  }
32. }
34. var b=new b ("B");
36. Console.log (b.name+ "" +b.showname () + "" +b.showtest ()); b b b (minus the comment The result is: b Soul b)

  Second, function.apply function    1, function.apply (obj,arguments) the args parameter will be passed to the function functions (starting with arguments[0] in turn 2. The code example is as follows: 

2. function A (NAMEA) {
4. This.name=namea;
6. This.showname=function () {
8. return this.name;
10. }
12. }
14. function B (NAMEA,NAMEB) {//parameter will be passed to a () sequentially, so the parameter of A is written in the front
16. var arr=new Array ();
18. Arr[0]=nameb;
20. A.apply (This,arr); Parameter must be an array
22. A.apply (this,arguments);
24. This.showtest=function () {
26. return NAMEB;
28. }
30. }
32. var b=new b ("A", "B");
34. Console.log (b.name+ "" +b.showname () + "" +b.showtest ()); A A B

 Third, apply other uses 1, Math.max.apply (Null,arr); Returns the maximum value of an array in arr 2, Array.prototype.push.apply (ARR1,ARR2); Adding arr2 to arr1 arr1 itself changes 

Call function and apply function