4 ways to call a function in JavaScript code instance _javascript tips

1: Method Invocation pattern

var myobj = {//object literal
  param1:1,
  param2:2,
  sum:function () {
//this keyword with only current object return
This.result = This.param1 + this.param2;
  }
}
Myobj.sum (); =>3

2: Function call mode

var add = function (A, b) {return
  a + b;
}
Function call Mode
add (1,2);//=>3

It's OK

function Add (A, b) {return
  a + b;
}
Add (1,2);//=>3

3: Constructor Call pattern

var add = function () {
  this.name = "remit Wisdom net";
  This.sum = function (A, b) {return
    a + b;
  }
}
constructor invocation pattern
var obj = new Add ();//obj is an object
obj.sum (1,2);//=>3

4:apply Call mode

var add = function (A, b) {return
  a + b;
}
 
Add.apply (null,[1,2]); =>3

You can also use call

var add = function (A, b) {return
  a + b;
}
Add.call (null,1,2); =>3