JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 224 · 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 = 28;
   books = books + 5;
   books = books - 27;
   console.log(books);
2. 2.⚡ What number does this code print?
   let runs = 28;
   runs = runs + 9;
   runs = runs - 36;
   console.log(runs);
3. 3.⚡ 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
4. 4.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) let (d) alert()
5. 5.⚡ What does this code show?
   let name = "Zoya";
   console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Zoya (d) Well done, Zoya!
6. 6.⚡ What number does this code print?
   let a = 4;
   let b = 4;
   console.log(a * b);
7. 7.⚡ What does this code show?
   let name = "Riya";
   console.log("Hi, " + name + "!"); (a) Riya (b) Hi, Riya! (c) Hi, name! (d) name
8. 8.⚡ What number does this code print?
   let a = 21;
   let b = 7;
   console.log(a + b);
9. 9.⚡ What does this code show?
   let name = "Aman";
   console.log("Hi, " + name + "!"); (a) Hi, Aman! (b) Aman (c) Hi, name! (d) name
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 8 (b) 71 (c) Error
11. 11.⚡ What number does this code print?
    let runs = 22;
    runs = runs + 11;
    runs = runs - 24;
    console.log(runs);
12. 12.⚡ Which JavaScript word repeats code? (a) if (b) for (c) let (d) console.log()
13. 13.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Zoya (b) name (c) Hi, Zoya! (d) Hi, name!
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) Error (b) 12 (c) 57
15. 15.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) on the printer (d) in the address bar
16. 16.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) let (c) alert() (d) if
17. 17.⚡ What number does this code print?
    let a = 2;
    let b = 3;
    console.log(a * b);
18. 18.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Riya! (d) Riya
19. 19.⚡ Which word makes a new variable? (a) put (b) make (c) let (d) give
20. 20.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, Zoya! (b) Hello, name! (c) Zoya (d) name
21. 21.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Riya (d) Welcome, Riya!
22. 22.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .jpg (d) .css
23. 23.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <style> (c) <code> (d) <script>
24. 24.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Zoya! (d) Zoya
25. 25.⚡ What number does this code print?
    let a = 57;
    let b = 9;
    console.log(a + b);
26. 26.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
27. 27.⚡ What number does this code print?
    let a = 3;
    let b = 11;
    console.log(a * b);
28. 28.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) console.log()
29. 29.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Meera (b) Hello, name! (c) name (d) Hello, Meera!
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 3;
    console.log(x + y); (a) 63 (b) 9 (c) Error
31. 31.⚡ Which JavaScript word runs code when true? (a) alert() (b) let (c) console.log() (d) if
32. 32.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a table (d) a picture
33. 33.⚡ What number does this code print?
    let a = 9;
    let b = 2;
    console.log(a * b);
34. 34.⚡ What number does this code print?
    let a = 42;
    let b = 29;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let a = 19;
    let b = 30;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let score = 21;
    score = score + 17;
    score = score - 11;
    console.log(score);
37. 37.⚡ What number does this code print?
    let marks = 26;
    marks = marks + 10;
    marks = marks - 21;
    console.log(marks);
38. 38.⚡ What number does this code print?
    let a = 58;
    let b = 33;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let apples = 30;
    apples = apples + 18;
    apples = apples - 5;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let a = 15;
    let b = 12;
    console.log(a + b);

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