JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 850 · 40 questions

Code tip (Line by line): let x = 5; makes a variable x holding 5; x = x + 2; changes it to 7. console.log(…) writes in the console; alert(…) shows a pop-up box. Text in quotes + anything = joined text: "5" + 3 → "53".

1. 1.⚡ What number does this code print?
   let marks = 21;
   marks = marks + 10;
   marks = marks - 21;
   console.log(marks);
2. 2.⚡ What number does this code print?
   let a = 9;
   let b = 6;
   console.log(a - b);
3. 3.⚡ Where does console.log() show its output? (a) on the printer (b) in the address bar (c) on the title bar (d) in the console
4. 4.⚡ What number does this code print?
   let runs = 11;
   runs = runs + 2;
   runs = runs - 1;
   console.log(runs);
5. 5.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) for (d) let
6. 6.⚡ What number does this code print?
   let a = 4;
   let b = 11;
   console.log(a * b);
7. 7.⚡ What number does this code print?
   let a = 3;
   let b = 3;
   console.log(a * b);
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) if (b) let (c) console.log() (d) alert()
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .jpg (d) .html
10. 10.⚡ Which JavaScript word writes in the console? (a) console.log() (b) let (c) for (d) alert()
11. 11.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <js> (d) <script>
12. 12.⚡ Which word makes a new variable? (a) let (b) give (c) put (d) make
13. 13.⚡ What number does this code print?
    let a = 6;
    let b = 7;
    console.log(a * b);
14. 14.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Well done, Zoya! (b) Well done, name! (c) Zoya (d) name
15. 15.⚡ What number does this code print?
    let a = 32;
    let b = 26;
    console.log(a - b);
16. 16.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Riya (b) Hello, name! (c) Hello, Riya! (d) name
17. 17.⚡ What number does this code print?
    let marks = 7;
    marks = marks + 12;
    marks = marks - 15;
    console.log(marks);
18. 18.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) Well done, Zoya! (b) name (c) Zoya (d) Well done, name!
19. 19.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
20. 20.⚡ What number does this code print?
    let a = 39;
    let b = 35;
    console.log(a - b);
21. 21.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Meera! (c) name (d) Meera
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) 58 (b) 13 (c) Error
23. 23.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) name (b) Aman (c) Hi, Aman! (d) Hi, name!
24. 24.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Aman (b) Welcome, Aman! (c) Welcome, name! (d) name
25. 25.⚡ What number does this code print?
    let a = 60;
    let b = 19;
    console.log(a - b);
26. 26.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) Riya (b) Hi, Riya! (c) Hi, name! (d) name
27. 27.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Hi, Riya! (c) name (d) Riya
28. 28.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 17;
    apples = apples - 9;
    console.log(apples);
29. 29.⚡ What number does this code print?
    let a = 34;
    let b = 6;
    console.log(a - b);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) 13 (c) Error
31. 31.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Kabir (d) Welcome, Kabir!
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) Error (b) 12 (c) 84
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) 17 (b) 8 (c) Error
34. 34.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Arjun (b) Welcome, name! (c) name (d) Welcome, Arjun!
35. 35.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Riya! (d) Riya
36. 36.⚡ What number does this code print?
    let a = 25;
    let b = 24;
    console.log(a - b);
37. 37.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, Riya! (b) name (c) Riya (d) Hello, name!
38. 38.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) console.log() (d) alert()
39. 39.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Meera (c) Hi, name! (d) Hi, Meera!
40. 40.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a table (d) a picture

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