JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 485 · 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 = 21;
   books = books + 20;
   books = books - 7;
   console.log(books);
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 3;
   console.log(x + y); (a) 93 (b) Error (c) 12
3. 3.⚡ Where does console.log() show its output? (a) on the title bar (b) in the console (c) on the printer (d) in the address bar
4. 4.⚡ What number does this code print?
   let apples = 11;
   apples = apples + 18;
   apples = apples - 7;
   console.log(apples);
5. 5.⚡ What does this code show?
   let name = "Meera";
   alert("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Meera (d) Well done, Meera!
6. 6.⚡ Which word makes a new variable? (a) make (b) put (c) let (d) give
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 2;
   console.log(x + y); (a) 22 (b) 4 (c) Error
8. 8.⚡ Which JavaScript word makes a new variable? (a) let (b) for (c) alert() (d) console.log()
9. 9.⚡ Which JavaScript word writes in the console? (a) for (b) console.log() (c) let (d) alert()
10. 10.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) the page title (d) only colours
11. 11.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Meera (b) Hi, name! (c) name (d) Hi, Meera!
12. 12.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .html (d) .jpg
13. 13.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) alert() (d) for
14. 14.⚡ What number does this code print?
    let a = 40;
    let b = 33;
    console.log(a - b);
15. 15.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) for (d) console.log()
16. 16.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Aman (d) Welcome, Aman!
17. 17.⚡ What number does this code print?
    let score = 9;
    score = score + 3;
    score = score - 4;
    console.log(score);
18. 18.⚡ What number does this code print?
    let score = 5;
    score = score + 5;
    score = score - 3;
    console.log(score);
19. 19.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <script> (d) <code>
20. 20.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a table (d) a new tab
21. 21.⚡ What number does this code print?
    let score = 22;
    score = score + 6;
    score = score - 21;
    console.log(score);
22. 22.⚡ What number does this code print?
    let a = 42;
    let b = 23;
    console.log(a + b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) Error (b) 8 (c) 53
24. 24.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 5;
    apples = apples - 5;
    console.log(apples);
25. 25.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Zoya (b) Hello, name! (c) Hello, Zoya! (d) name
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) Error (b) 16 (c) 97
27. 27.⚡ What number does this code print?
    let marks = 23;
    marks = marks + 3;
    marks = marks - 2;
    console.log(marks);
28. 28.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 3;
    apples = apples - 5;
    console.log(apples);
29. 29.⚡ What number does this code print?
    let score = 25;
    score = score + 18;
    score = score - 27;
    console.log(score);
30. 30.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 18;
    runs = runs - 29;
    console.log(runs);
31. 31.⚡ What number does this code print?
    let score = 21;
    score = score + 4;
    score = score - 3;
    console.log(score);
32. 32.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, Zoya! (b) Hello, name! (c) Zoya (d) name
33. 33.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Meera! (d) Meera
34. 34.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Meera (c) Welcome, Meera! (d) name
35. 35.⚡ What number does this code print?
    let score = 6;
    score = score + 13;
    score = score - 8;
    console.log(score);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 9;
    console.log(x + y); (a) 29 (b) 11 (c) Error
37. 37.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 16;
    coins = coins - 3;
    console.log(coins);
38. 38.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Kabir! (d) Kabir
39. 39.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Riya! (c) Welcome, name! (d) Riya
40. 40.⚡ What number does this code print?
    let a = 54;
    let b = 18;
    console.log(a - b);

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