Question

What will happen if we execute the following piece of code?

<script>  

  

var arr=[4,3,,1];    

  for(i=0;i<4;i++){  

document.writeln(arr[i]);  

}  

</script>  
 

a) The output will be 4 3 1

b) The output will be 4 3 undefined 1

c) It will result in an error

d) It does not run at all

Answer 1

Answer: B

Reason: In JavaScript, if user defines an array and does not define value of any element, there will be no error. But if user tries to print the element of the array whose value is not defined, it will print the "undefined" as the value of that element.