Sample Javascript Interview Questions

//1

//what value will show with the alert?

test = "herby";

{

    var test = "not herby";

}

alert(test);

//1

//2

//what value will show with the alerts?

//how would you write this differently

function triple(x)

{

i= 3;

return x * i;

}

var i =2;

alert(triple(i)) ;

alert(i);

//2

//3

//will this run? why or why not?

var o = new Object;

o.totriple = triple;

with(o)

{

alert(totriple(5));

}

//

//4

//what are the results and why

alert("1"==true);

alert("1"===true);

//

//5

//what value will show with the alert?

//this applies to other languages also

var x = 1;

var y = x++;

alert(y);

//5

//6

//will the alert run?

//bonus - what is this called?

if(x==0 && y ==0);

alert("can this be?");

//

//7

//what are the results here?

alert("1" + 2);

alert(1 + "2");

alert(1 + 2 + " hello");

alert(" hello" + 1 + 2);

alert("19" < "2");

//7

//8

//question - can you make javascript mimic c#'s startwith function for strings?

String.prototype.startsWith = function(s){ return (this.substr(0, s.length) == s)  }

var test ="test";

alert(test.startsWith("te"));

alert(test.startsWith("ete")); 

//8

//9

//what value is num?  

var num = 34/0;

alert(num);

//9

//10

//will the value be true and why?

//is there any way of doing this?

var num2 = 0/0;

var num3 = 0/0;

alert(num2==num3);

//10

//11

//what will show?

alert("n\n\\n");

//11

//12

//is the if statement true

var num4;

if(num4===null)

  alert("here");

//12

//13
var t   = 0||67;alert(t); 
//13