Javascript interview questions part 3
Javascript interview questions part 3
Take as many assements as you can to improve your validate your skill rating
Total Questions: 20
1. Which event handler is triggered when the user’s mouse moves away from a link?
Correct Answer is : onMouseOut
2. Consider the code snippet given below var count = [1,,3]; What is the observation made?
Correct Answer is : The omitted value takes “undefined”
3. Consider the following code snippet var a1 = [,,,]; var a2 = new Array(3); 0 in a1 0 in a2 The result would be
Correct Answer is : true false
4. The pop() method of the array does which of the following task ?
Correct Answer is : decrements the total length by 1
5. Consider the following code snippet : if (!a[i]) continue; What is the observation made ?
Correct Answer is : All of the mentioned
6. What will happen if reverse() and join() methods are used simultaneously?
Correct Answer is : Reverses and stores in the same array
7. Consider the following code snippet : var a = [1,2,3,4,5]; a.slice(0,3); What is the possible output for the above code snippet ?
Correct Answer is : Returns [1,2,3,4].
8. Consider the following code snippet : var a = []; a.unshift(1); a.unshift(22); a.shift(); a.unshift(3,[4,5]); a.shift(); a.shift(); a.shift(); The final output for the shift() is
Correct Answer is : 1
9. The primary purpose of the array map() function is that it
Correct Answer is : passes each element of the array on which it is invoked to the function you specify, and returns an array containing the values returned by that function
10. The reduce and reduceRight methods follow a common operation called
Correct Answer is : inject and fold
11. The method or operator used to identify the array is
Correct Answer is : typeof
12. Which is a fast C++ based JavaScript interpreter?
Correct Answer is : Node
13. Why does the Node rely on event handlers?
Correct Answer is : APIs are asynchronous
14. What is the command to run the node programs?
Correct Answer is : node program.js
15. What is the alternative command used in Node for load()?
Correct Answer is : require()
16. What is the command used for debugging output in Node?
Correct Answer is : console.log(…);
17. What is the code to print hello one second from now?
Correct Answer is : setTimeout(function() { console.log("Hello World"); }, 1000);
18. Among the below given functions, Node supports which of the following client-side timer functions?
Correct Answer is : clearTimeout()
19. The necessary globals of a node are defined under which namespace?
Correct Answer is : process
20. Why does Node not block while waiting for operations to complete?
Correct Answer is : Asynchronous
