4 ways to call functions in JavaScript code examples_javascript skills

1: Method calling mode

var myObj = {//对象字面量
  param1: 1,
  param2: 2,
  sum: function (){
//this关键字只带当前的对象
return this.result = this.param1 + this.param2;
  }
}
myObj.sum(); //=>3

2: Function calling mode

var add = function(a, b){
  return a + b;
}
//函数调用模式
add(1,2); //=>3

Alright

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

3: Constructor calling mode

var add = function() {
  this.name = "汇智网";
  this.sum = function (a, b){
    return a + b;
  }
}
// 构造器调用模式
var obj = new add(); //obj是一个对象
obj.sum(1,2); //=>3

4: apply calling 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