JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 389 · 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 books = 15;
   books = books + 17;
   books = books - 7;
   console.log(books);
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) for (d) if
3. 3.⚡ Which JavaScript word runs code when true? (a) for (b) alert() (c) let (d) if
4. 4.⚡ What number does this code print?
   let a = 36;
   let b = 13;
   console.log(a - b);
5. 5.⚡ What number does this code print?
   let a = 35;
   let b = 21;
   console.log(a - b);
6. 6.⚡ Which JavaScript word makes a new variable? (a) for (b) console.log() (c) let (d) if
7. 7.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) name
8. 8.⚡ What number does this code print?
   let books = 24;
   books = books + 3;
   books = books - 9;
   console.log(books);
9. 9.⚡ What does alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
10. 10.⚡ What number does this code print?
    let score = 10;
    score = score + 5;
    score = score - 4;
    console.log(score);
11. 11.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Riya (c) name (d) Hello, Riya!
12. 12.⚡ What number does this code print?
    let a = 36;
    let b = 31;
    console.log(a - b);
13. 13.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Meera (d) Welcome, Meera!
14. 14.⚡ What number does this code print?
    let a = 36;
    let b = 36;
    console.log(a + b);
15. 15.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .js (d) .css
16. 16.⚡ What number does this code print?
    let a = 43;
    let b = 12;
    console.log(a + b);
17. 17.⚡ Which JavaScript word repeats code? (a) for (b) console.log() (c) alert() (d) if
18. 18.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Riya (c) Welcome, name! (d) Welcome, Riya!
19. 19.⚡ What number does this code print?
    let a = 9;
    let b = 9;
    console.log(a * b);
20. 20.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Zoya (b) Hello, name! (c) name (d) Hello, Zoya!
21. 21.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
22. 22.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Arjun! (c) Hi, name! (d) Arjun
23. 23.⚡ Which JavaScript word writes in the console? (a) let (b) console.log() (c) for (d) if
24. 24.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a + b);
25. 25.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 8;
    apples = apples - 5;
    console.log(apples);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) Error (b) 14 (c) 5
27. 27.⚡ What number does this code print?
    let a = 9;
    let b = 37;
    console.log(a + b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 18 (b) 99 (c) Error
29. 29.⚡ What number does this code print?
    let runs = 16;
    runs = runs + 13;
    runs = runs - 5;
    console.log(runs);
30. 30.⚡ What number does this code print?
    let books = 21;
    books = books + 7;
    books = books - 16;
    console.log(books);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) Error (b) 13 (c) 94
32. 32.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) Error (b) 10 (c) 91
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 41 (b) Error (c) 5
35. 35.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Meera! (c) Meera (d) Well done, name!
36. 36.⚡ What number does this code print?
    let a = 10;
    let b = 9;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let a = 29;
    let b = 10;
    console.log(a - b);
38. 38.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Kabir (b) name (c) Hi, Kabir! (d) Hi, name!
39. 39.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) Welcome, name! (c) Kabir (d) name
40. 40.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Aman (c) Well done, Aman! (d) name

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