JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 525 · 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 a = 2;
   let b = 3;
   console.log(a * b);
2. 2.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
3. 3.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
4. 4.⚡ Which word makes a new variable? (a) let (b) put (c) make (d) give
5. 5.⚡ Which JavaScript word writes in the console? (a) let (b) alert() (c) console.log() (d) if
6. 6.⚡ What number does this code print?
   let apples = 16;
   apples = apples + 9;
   apples = apples - 10;
   console.log(apples);
7. 7.⚡ What does this code show?
   let name = "Meera";
   alert("Well done, " + name + "!"); (a) Well done, Meera! (b) Well done, name! (c) name (d) Meera
8. 8.⚡ What does this code show?
   let name = "Zoya";
   alert("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Zoya! (d) Zoya
9. 9.⚡ What number does this code print?
   let coins = 19;
   coins = coins + 10;
   coins = coins - 16;
   console.log(coins);
10. 10.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <script> (d) <code>
11. 11.⚡ What number does this code print?
    let a = 40;
    let b = 21;
    console.log(a + b);
12. 12.⚡ What number does this code print?
    let score = 22;
    score = score + 3;
    score = score - 12;
    console.log(score);
13. 13.⚡ Which JavaScript word repeats code? (a) let (b) for (c) if (d) console.log()
14. 14.⚡ What number does this code print?
    let runs = 25;
    runs = runs + 3;
    runs = runs - 16;
    console.log(runs);
15. 15.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) for (d) let
16. 16.⚡ What number does this code print?
    let a = 25;
    let b = 39;
    console.log(a + b);
17. 17.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) for (c) if (d) console.log()
18. 18.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
19. 19.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
20. 20.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) name (b) Kabir (c) Welcome, Kabir! (d) Welcome, name!
21. 21.⚡ What number does this code print?
    let a = 18;
    let b = 11;
    console.log(a + b);
22. 22.⚡ What number does this code print?
    let runs = 30;
    runs = runs + 4;
    runs = runs - 14;
    console.log(runs);
23. 23.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 12;
    runs = runs - 13;
    console.log(runs);
24. 24.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Hi, Meera! (b) name (c) Hi, name! (d) Meera
25. 25.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) Well done, Aman! (d) name
26. 26.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Riya! (c) Riya (d) Hello, name!
27. 27.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) let (c) alert() (d) if
28. 28.⚡ What number does this code print?
    let a = 51;
    let b = 7;
    console.log(a - b);
29. 29.⚡ 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
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) Error (b) 11 (c) 65
31. 31.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 17;
    coins = coins - 8;
    console.log(coins);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 93 (b) 12 (c) Error
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 16 (b) Error (c) 97
34. 34.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Zoya! (c) Zoya (d) Well done, name!
35. 35.⚡ What number does this code print?
    let score = 19;
    score = score + 18;
    score = score - 22;
    console.log(score);
36. 36.⚡ What number does this code print?
    let a = 33;
    let b = 4;
    console.log(a + b);
37. 37.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Riya (c) Welcome, Riya! (d) Welcome, name!
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) 88 (b) Error (c) 16
39. 39.⚡ 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
40. 40.⚡ What number does this code print?
    let a = 10;
    let b = 11;
    console.log(a + b);

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