JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 650 · 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 runs = 28;
   runs = runs + 13;
   runs = runs - 10;
   console.log(runs);
2. 2.⚡ Which word makes a new variable? (a) make (b) let (c) give (d) put
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) if (b) alert() (c) for (d) let
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 3;
   console.log(x + y); (a) 33 (b) Error (c) 6
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 5;
   console.log(x + y); (a) Error (b) 7 (c) 25
6. 6.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) alert() (d) console.log()
7. 7.⚡ What does this code show?
   let name = "Zoya";
   alert("Hi, " + name + "!"); (a) Hi, name! (b) Zoya (c) name (d) Hi, Zoya!
8. 8.⚡ What number does this code print?
   let coins = 7;
   coins = coins + 11;
   coins = coins - 15;
   console.log(coins);
9. 9.⚡ What number does this code print?
   let a = 19;
   let b = 3;
   console.log(a - b);
10. 10.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) for (d) if
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 5 (b) 41 (c) Error
12. 12.⚡ What number does this code print?
    let score = 11;
    score = score + 5;
    score = score - 10;
    console.log(score);
13. 13.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .jpg (d) .html
14. 14.⚡ What number does this code print?
    let a = 15;
    let b = 6;
    console.log(a - b);
15. 15.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Riya! (d) Riya
16. 16.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, Kabir! (b) name (c) Hello, name! (d) Kabir
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) Hello, Meera! (d) name
18. 18.⚡ What number does this code print?
    let books = 21;
    books = books + 12;
    books = books - 31;
    console.log(books);
19. 19.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) actions and changes (d) the page title
20. 20.⚡ What number does this code print?
    let a = 22;
    let b = 16;
    console.log(a - b);
21. 21.⚡ What number does this code print?
    let a = 12;
    let b = 4;
    console.log(a * b);
22. 22.⚡ What number does this code print?
    let a = 42;
    let b = 35;
    console.log(a - b);
23. 23.⚡ What number does this code print?
    let a = 15;
    let b = 6;
    console.log(a + b);
24. 24.⚡ What number does this code print?
    let a = 15;
    let b = 5;
    console.log(a - b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 64 (b) Error (c) 10
26. 26.⚡ What number does this code print?
    let a = 41;
    let b = 29;
    console.log(a + b);
27. 27.⚡ What number does this code print?
    let a = 19;
    let b = 30;
    console.log(a + b);
28. 28.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) name (b) Hello, Arjun! (c) Arjun (d) Hello, name!
29. 29.⚡ Which JavaScript word makes a new variable? (a) let (b) if (c) for (d) alert()
30. 30.⚡ What does alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
31. 31.⚡ What number does this code print?
    let a = 11;
    let b = 12;
    console.log(a * b);
32. 32.⚡ What number does this code print?
    let a = 34;
    let b = 13;
    console.log(a - b);
33. 33.⚡ What number does this code print?
    let apples = 16;
    apples = apples + 9;
    apples = apples - 2;
    console.log(apples);
34. 34.⚡ 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!
35. 35.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <style> (d) <js>
36. 36.⚡ What number does this code print?
    let a = 8;
    let b = 29;
    console.log(a + b);
37. 37.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) in the address bar (d) on the title bar
38. 38.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Riya (c) name (d) Hi, Riya!
39. 39.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 6;
    coins = coins - 1;
    console.log(coins);
40. 40.⚡ What number does this code print?
    let score = 29;
    score = score + 2;
    score = score - 14;
    console.log(score);

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