JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 204 · 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 = 10;
   let b = 26;
   console.log(a + b);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 5;
   console.log(x + y); (a) 15 (b) Error (c) 6
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) if (b) console.log() (c) for (d) alert()
4. 4.⚡ What number does this code print?
   let a = 4;
   let b = 10;
   console.log(a * b);
5. 5.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
6. 6.⚡ What number does this code print?
   let apples = 20;
   apples = apples + 5;
   apples = apples - 2;
   console.log(apples);
7. 7.⚡ What does this code show?
   let name = "Meera";
   alert("Hello, " + name + "!"); (a) Hello, Meera! (b) Hello, name! (c) name (d) Meera
8. 8.⚡ What number does this code print?
   let a = 2;
   let b = 4;
   console.log(a * b);
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .css (d) .js
10. 10.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Zoya (c) Hello, Zoya! (d) name
11. 11.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 2;
    coins = coins - 7;
    console.log(coins);
12. 12.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, name! (d) Welcome, Aman!
13. 13.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <code> (d) <js>
14. 14.⚡ What number does this code print?
    let score = 28;
    score = score + 20;
    score = score - 25;
    console.log(score);
15. 15.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
16. 16.⚡ Which JavaScript word repeats code? (a) let (b) for (c) console.log() (d) alert()
17. 17.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) let (d) console.log()
18. 18.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 17;
    apples = apples - 22;
    console.log(apples);
19. 19.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 7;
    apples = apples - 12;
    console.log(apples);
20. 20.⚡ What number does this code print?
    let a = 53;
    let b = 5;
    console.log(a - b);
21. 21.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Well done, Aman! (b) Well done, name! (c) Aman (d) name
22. 22.⚡ What number does this code print?
    let coins = 7;
    coins = coins + 7;
    coins = coins - 6;
    console.log(coins);
23. 23.⚡ Which JavaScript word writes in the console? (a) console.log() (b) if (c) alert() (d) for
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) Error (b) 58 (c) 13
25. 25.⚡ What number does this code print?
    let a = 37;
    let b = 12;
    console.log(a + b);
26. 26.⚡ What number does this code print?
    let a = 10;
    let b = 12;
    console.log(a * b);
27. 27.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, name! (c) name (d) Hi, Arjun!
28. 28.⚡ What number does this code print?
    let runs = 27;
    runs = runs + 5;
    runs = runs - 11;
    console.log(runs);
29. 29.⚡ What number does this code print?
    let a = 24;
    let b = 9;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let runs = 26;
    runs = runs + 15;
    runs = runs - 5;
    console.log(runs);
31. 31.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) on the title bar (d) in the address bar
32. 32.⚡ Which word makes a new variable? (a) give (b) let (c) put (d) make
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) 10 (b) Error (c) 91
34. 34.⚡ What number does this code print?
    let a = 5;
    let b = 30;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let a = 38;
    let b = 9;
    console.log(a - b);
36. 36.⚡ Which JavaScript word makes a new variable? (a) if (b) for (c) let (d) console.log()
37. 37.⚡ What number does this code print?
    let score = 7;
    score = score + 3;
    score = score - 5;
    console.log(score);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) Error (b) 3 (c) 12
39. 39.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Meera (c) name (d) Well done, Meera!
40. 40.⚡ What number does this code print?
    let a = 11;
    let b = 10;
    console.log(a - b);

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