JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 837 · 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 alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
2. 2.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) for (d) console.log()
3. 3.⚡ Which JavaScript word runs code when true? (a) let (b) if (c) console.log() (d) for
4. 4.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <code> (c) <script> (d) <style>
5. 5.⚡ What number does this code print?
   let a = 25;
   let b = 15;
   console.log(a + b);
6. 6.⚡ Which JavaScript word writes in the console? (a) for (b) console.log() (c) if (d) alert()
7. 7.⚡ What number does this code print?
   let a = 34;
   let b = 30;
   console.log(a + b);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 5;
   console.log(x + y); (a) 11 (b) 65 (c) Error
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 2;
   console.log(x + y); (a) 8 (b) 62 (c) Error
10. 10.⚡ What number does this code print?
    let marks = 21;
    marks = marks + 17;
    marks = marks - 1;
    console.log(marks);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 8;
    console.log(x + y); (a) Error (b) 48 (c) 12
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 8 (b) Error (c) 26
13. 13.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the title bar (d) on the printer
14. 14.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 15;
    coins = coins - 1;
    console.log(coins);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) Error (c) 53
16. 16.⚡ Which JavaScript word shows a pop-up box? (a) let (b) if (c) for (d) alert()
17. 17.⚡ What number does this code print?
    let a = 13;
    let b = 9;
    console.log(a - b);
18. 18.⚡ What number does this code print?
    let a = 9;
    let b = 5;
    console.log(a * b);
19. 19.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) Hello, Riya! (c) Hello, name! (d) name
20. 20.⚡ Which word makes a new variable? (a) make (b) let (c) give (d) put
21. 21.⚡ What number does this code print?
    let a = 56;
    let b = 40;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 8;
    apples = apples - 24;
    console.log(apples);
23. 23.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, Kabir! (c) name (d) Hello, name!
24. 24.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 3;
    marks = marks - 3;
    console.log(marks);
25. 25.⚡ What number does this code print?
    let a = 2;
    let b = 5;
    console.log(a * b);
26. 26.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) for (c) let (d) if
27. 27.⚡ What number does this code print?
    let a = 56;
    let b = 25;
    console.log(a - b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 78 (b) 15 (c) Error
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) Error (b) 10 (c) 64
30. 30.⚡ What number does this code print?
    let coins = 5;
    coins = coins + 4;
    coins = coins - 2;
    console.log(coins);
31. 31.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .html (d) .css
32. 32.⚡ What number does this code print?
    let a = 5;
    let b = 8;
    console.log(a * b);
33. 33.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) the domain name (d) actions and changes
34. 34.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Meera (d) Hi, Meera!
35. 35.⚡ What number does this code print?
    let a = 43;
    let b = 37;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let a = 10;
    let b = 20;
    console.log(a + b);
37. 37.⚡ What number does this code print?
    let a = 10;
    let b = 2;
    console.log(a * b);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) Error (b) 9 (c) 81
39. 39.⚡ What number does this code print?
    let a = 19;
    let b = 15;
    console.log(a - b);
40. 40.⚡ What number does this code print?
    let score = 20;
    score = score + 15;
    score = score - 10;
    console.log(score);

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