JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 458 · 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 writes in the console? (a) alert() (b) for (c) let (d) console.log()
2. 2.⚡ Which JavaScript word runs code when true? (a) console.log() (b) alert() (c) for (d) if
3. 3.⚡ What number does this code print?
   let apples = 15;
   apples = apples + 3;
   apples = apples - 7;
   console.log(apples);
4. 4.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <js> (d) <script>
5. 5.⚡ What number does this code print?
   let a = 12;
   let b = 8;
   console.log(a - b);
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 5;
   console.log(x + y); (a) 55 (b) 10 (c) Error
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 7;
   console.log(x + y); (a) Error (b) 13 (c) 67
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 3;
   console.log(x + y); (a) 12 (b) 93 (c) Error
9. 9.⚡ Which word makes a new variable? (a) let (b) make (c) give (d) put
10. 10.⚡ What number does this code print?
    let coins = 29;
    coins = coins + 10;
    coins = coins - 12;
    console.log(coins);
11. 11.⚡ What number does this code print?
    let books = 8;
    books = books + 11;
    books = books - 14;
    console.log(books);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 12 (b) 75 (c) Error
13. 13.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) name (c) Hello, name! (d) Aman
14. 14.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Kabir (b) name (c) Welcome, Kabir! (d) Welcome, name!
15. 15.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 6;
    runs = runs - 14;
    console.log(runs);
16. 16.⚡ What number does this code print?
    let score = 17;
    score = score + 6;
    score = score - 1;
    console.log(score);
17. 17.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) if (d) for
18. 18.⚡ What number does this code print?
    let a = 4;
    let b = 4;
    console.log(a * b);
19. 19.⚡ What number does this code print?
    let books = 10;
    books = books + 19;
    books = books - 11;
    console.log(books);
20. 20.⚡ What number does this code print?
    let a = 9;
    let b = 38;
    console.log(a + b);
21. 21.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .jpg (d) .html
22. 22.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) for
23. 23.⚡ What number does this code print?
    let a = 58;
    let b = 37;
    console.log(a + b);
24. 24.⚡ Which JavaScript word repeats code? (a) let (b) for (c) console.log() (d) alert()
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 9;
    console.log(x + y); (a) 14 (b) Error (c) 59
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 1;
    console.log(x + y); (a) 61 (b) Error (c) 7
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 23 (b) 5 (c) Error
28. 28.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, Riya! (b) Riya (c) name (d) Well done, name!
29. 29.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) on the printer (d) in the address bar
30. 30.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) actions and changes (d) only colours
31. 31.⚡ What number does this code print?
    let runs = 30;
    runs = runs + 17;
    runs = runs - 29;
    console.log(runs);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 5;
    console.log(x + y); (a) Error (b) 95 (c) 14
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 9;
    console.log(x + y); (a) 16 (b) 79 (c) Error
34. 34.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) name (c) Welcome, name! (d) Welcome, Zoya!
35. 35.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 8;
    apples = apples - 15;
    console.log(apples);
36. 36.⚡ What number does this code print?
    let a = 55;
    let b = 35;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let books = 19;
    books = books + 6;
    books = books - 10;
    console.log(books);
38. 38.⚡ What number does this code print?
    let a = 5;
    let b = 9;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 8;
    let b = 25;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let a = 42;
    let b = 4;
    console.log(a - b);

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