JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 528 · 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 does this code print? (Look at the quotes!)
   let x = "2";
   let y = 3;
   console.log(x + y); (a) Error (b) 5 (c) 23
2. 2.⚡ What number does this code print?
   let a = 3;
   let b = 6;
   console.log(a * b);
3. 3.⚡ What does alert() show? (a) a picture (b) a table (c) a new tab (d) a pop-up box
4. 4.⚡ What number does this code print?
   let a = 29;
   let b = 5;
   console.log(a - b);
5. 5.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
6. 6.⚡ What number does this code print?
   let score = 27;
   score = score + 15;
   score = score - 19;
   console.log(score);
7. 7.⚡ What number does this code print?
   let a = 39;
   let b = 12;
   console.log(a - b);
8. 8.⚡ What number does this code print?
   let a = 37;
   let b = 25;
   console.log(a + b);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 8;
   console.log(x + y); (a) 14 (b) Error (c) 68
10. 10.⚡ What number does this code print?
    let apples = 17;
    apples = apples + 18;
    apples = apples - 1;
    console.log(apples);
11. 11.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) for (c) let (d) console.log()
13. 13.⚡ What number does this code print?
    let a = 55;
    let b = 31;
    console.log(a - b);
14. 14.⚡ What number does this code print?
    let a = 60;
    let b = 28;
    console.log(a - b);
15. 15.⚡ What number does this code print?
    let score = 16;
    score = score + 5;
    score = score - 11;
    console.log(score);
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
17. 17.⚡ What number does this code print?
    let a = 9;
    let b = 8;
    console.log(a * b);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 31 (c) 4
19. 19.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) name (c) Hi, Arjun! (d) Hi, name!
20. 20.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a * b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) 5 (b) Error (c) 14
22. 22.⚡ Which JavaScript word writes in the console? (a) for (b) console.log() (c) if (d) alert()
23. 23.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Zoya (b) Well done, name! (c) name (d) Well done, Zoya!
24. 24.⚡ What number does this code print?
    let a = 6;
    let b = 10;
    console.log(a * b);
25. 25.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Riya! (c) Hi, name! (d) Riya
26. 26.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) alert() (d) let
27. 27.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, Arjun! (b) name (c) Well done, name! (d) Arjun
28. 28.⚡ Which JavaScript word makes a new variable? (a) for (b) alert() (c) let (d) console.log()
29. 29.⚡ What number does this code print?
    let a = 30;
    let b = 22;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 5;
    apples = apples - 4;
    console.log(apples);
31. 31.⚡ Where does console.log() show its output? (a) on the title bar (b) in the console (c) in the address bar (d) on the printer
32. 32.⚡ What number does this code print?
    let score = 23;
    score = score + 5;
    score = score - 13;
    console.log(score);
33. 33.⚡ What number does this code print?
    let a = 33;
    let b = 19;
    console.log(a - b);
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) name (b) Aman (c) Well done, name! (d) Well done, Aman!
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 97 (b) 16 (c) Error
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) Error (b) 71 (c) 8
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 15 (b) 78 (c) Error
38. 38.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) Hello, Kabir! (d) name
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 13 (b) 85 (c) Error
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) 55 (b) Error (c) 10

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