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Showing posts with the label Inheritance

Difference between var, let and const

var, let and const in Javascript
 Variable can be declared in three ways: varletconstvar variables are function-wide scoped. Let's understand this with an example,    if(true){
      var x = 5;    // variable declared with "var"         console.log(x);  // x will be 5
 console.log(x); // even here, x will be 5 
So in the last example we can see variable "x" is available outside the "if" block, that means the scope of variable with "var" is not block scope.
let see with another example,
1.  function helloWorld(){      var x = 5;
2.     function abc(){
3.        console.log(x);      // even x will be 5
4.     }
5.     abc();
6.     console.log(x);  // x will be 5
7. }
8. helloWorld(); So in this example, we can see the variable "x" is available throughout the function in which it is declared.
One of the famous example/question discussed in the interviews is following
1.       for(var i=0;i<5;i++){
2.                console.log(i);
3.       }