JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 89 · 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.⚡ Which JavaScript word shows a pop-up box? (a) let (b) for (c) alert() (d) console.log()
2. 2.⚡ What number does this code print?
   let a = 25;
   let b = 11;
   console.log(a + b);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 6;
   console.log(x + y); (a) 16 (b) 7 (c) Error
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 4;
   console.log(x + y); (a) 12 (b) 84 (c) Error
5. 5.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <style> (d) <code>
6. 6.⚡ Which word makes a new variable? (a) let (b) give (c) put (d) make
7. 7.⚡ What does this code show?
   let name = "Aman";
   alert("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) Well done, Aman! (d) name
8. 8.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) if
9. 9.⚡ What does this code show?
   let name = "Kabir";
   alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Kabir (d) Well done, Kabir!
10. 10.⚡ Which JavaScript word writes in the console? (a) for (b) alert() (c) console.log() (d) let
11. 11.⚡ What number does this code print?
    let a = 11;
    let b = 4;
    console.log(a - b);
12. 12.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console
13. 13.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a table (d) a new tab
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) Error (b) 9 (c) 45
15. 15.⚡ What number does this code print?
    let a = 8;
    let b = 2;
    console.log(a * b);
16. 16.⚡ What number does this code print?
    let a = 10;
    let b = 6;
    console.log(a * b);
17. 17.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Kabir (c) name (d) Well done, Kabir!
18. 18.⚡ What number does this code print?
    let a = 16;
    let b = 5;
    console.log(a + b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 8;
    console.log(x + y); (a) 48 (b) 12 (c) Error
20. 20.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) Error (b) 2 (c) 11
22. 22.⚡ What number does this code print?
    let a = 54;
    let b = 2;
    console.log(a + b);
23. 23.⚡ What number does this code print?
    let score = 20;
    score = score + 19;
    score = score - 9;
    console.log(score);
24. 24.⚡ What number does this code print?
    let apples = 12;
    apples = apples + 12;
    apples = apples - 11;
    console.log(apples);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 3 (b) 21 (c) Error
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 52 (b) 7 (c) Error
27. 27.⚡ What number does this code print?
    let a = 28;
    let b = 10;
    console.log(a + b);
28. 28.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) console.log() (d) if
29. 29.⚡ What number does this code print?
    let a = 17;
    let b = 29;
    console.log(a + b);
30. 30.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
31. 31.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Riya! (d) Riya
32. 32.⚡ What number does this code print?
    let coins = 24;
    coins = coins + 2;
    coins = coins - 15;
    console.log(coins);
33. 33.⚡ Which JavaScript word repeats code? (a) if (b) for (c) console.log() (d) alert()
34. 34.⚡ What number does this code print?
    let books = 15;
    books = books + 11;
    books = books - 22;
    console.log(books);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) Error (b) 26 (c) 8
36. 36.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Meera (c) Hi, Meera! (d) Hi, name!
37. 37.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 8;
    runs = runs - 8;
    console.log(runs);
38. 38.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 4;
    apples = apples - 23;
    console.log(apples);
39. 39.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 6;
    apples = apples - 1;
    console.log(apples);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) 47 (b) Error (c) 11

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