JavaScript Questions

1. How does forEach() method differ from a for statement?

2. When the switch statement matches the expression with the given labels, how is the comparison done?

3. What will be the output of the following code snippet?

(function(){
 setTimeout(()=> console.log(1),2000);
 console.log(2);
 setTimeout(()=> console.log(3),0);
 console.log(4);
})();

4. What will be the output of the following JavaScript code?

let x = "10";
    let y = + x;
    
    document.write(typeof y);

5. What is the code for getting the current time?

6. What will be the output of the following code snippet?

var x=12;
var y=8;
var res=eval("x+y");
document.write(res);

7. What will be the output of the following JavaScript code?

var quiz=[1,2,3];
var js=[6,7,8];
var result=quiz.concat(js);
document.writeln(result);

8. How are windows, tabs, iframes, and frames treated according to client-side javascript?

9. Which of the following is a valid function to truncate number of full minutes between two time stamps?

10. Which JavaScript method is used to create a new array with array elements that passes a test?

11. Which is the function used to call a function in every time duration?

12. What will be the output of the following code snippet?

var a = "Scaler";
var result = a.substring(2, 4);
document.write(result);

13. Which handler is triggered when the content of the document in the window is stable and ready for manipulation?

14. Which JavaScript method is used to access an HTML element by id?

15. Which function is used to serialize an object into a JSON string in Javascript?