JS beginner to expert, study notes-4 (sec-9 loops)

For-in loop is like foreach loop of php. It iterates through any object or array….

1. For-in loop iterates through an object.

   // for-in loop in Objects
   
   var person ={
   	name: "sajib",
   	surname: "biswas",
   	age: 34
   };
   
   for (var property in person){
   	alert(property);			//Alerts name / surname / age
   	alert(property[property]);	//Alerts sajib / biswas / 34
   }
   
   // for-in loop in Array
   
   courses = ["sass", "less", "angular"];
   
   for (var property in courses){
   	alert(property);			//0, 1, 2  
   	alert(courses[property]);	// sass, less, angular 
   }

    

2. When a function is invoked, an Object called arguments is created inside that function which contains all parameters which were sent…

   // Arguments Object is found inside any function. It holds all arguments which were received by that function 
   
   function addNumbers(){
   	
   	var sum = 0;
   
   	for (var property in arguments){
   		sum += arguments[property];
   	}
   	
   	return sum;
   }
   
   alert( addNumbers(5, 5, 10) );