JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 457 · 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 = 9;
   console.log(a * b);
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) if (c) alert() (d) let
3. 3.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) in the address bar (d) on the title bar
4. 4.⚡ What does this code show?
   let name = "Riya";
   console.log("Hi, " + name + "!"); (a) Riya (b) name (c) Hi, Riya! (d) Hi, name!
5. 5.⚡ What number does this code print?
   let apples = 25;
   apples = apples + 18;
   apples = apples - 43;
   console.log(apples);
6. 6.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 6;
   console.log(x + y); (a) 96 (b) 15 (c) Error
8. 8.⚡ What number does this code print?
   let a = 11;
   let b = 9;
   console.log(a * b);
9. 9.⚡ What does JavaScript add to a web page? (a) actions and changes (b) only colours (c) the domain name (d) the page title
10. 10.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) for (d) if
11. 11.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
12. 12.⚡ Which JavaScript word repeats code? (a) alert() (b) if (c) console.log() (d) for
13. 13.⚡ Which JavaScript word writes in the console? (a) console.log() (b) for (c) alert() (d) let
14. 14.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .jpg (c) .css (d) .js
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 8;
    console.log(x + y); (a) 98 (b) Error (c) 17
16. 16.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 16;
    marks = marks - 11;
    console.log(marks);
17. 17.⚡ What number does this code print?
    let a = 10;
    let b = 7;
    console.log(a - b);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) 7 (b) Error (c) 34
19. 19.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Kabir! (c) Welcome, name! (d) Kabir
20. 20.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) alert() (d) for
21. 21.⚡ What number does this code print?
    let a = 41;
    let b = 8;
    console.log(a + b);
22. 22.⚡ What number does this code print?
    let a = 25;
    let b = 29;
    console.log(a + b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 1;
    console.log(x + y); (a) Error (b) 9 (c) 81
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) 84 (b) Error (c) 12
25. 25.⚡ What number does this code print?
    let a = 3;
    let b = 2;
    console.log(a * b);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) 10 (b) Error (c) 28
27. 27.⚡ What number does this code print?
    let apples = 19;
    apples = apples + 10;
    apples = apples - 9;
    console.log(apples);
28. 28.⚡ Which word makes a new variable? (a) give (b) make (c) put (d) let
29. 29.⚡ What number does this code print?
    let a = 12;
    let b = 7;
    console.log(a * b);
30. 30.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Kabir! (c) Kabir (d) Hi, name!
31. 31.⚡ What number does this code print?
    let a = 5;
    let b = 37;
    console.log(a + b);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 5;
    console.log(x + y); (a) 75 (b) Error (c) 12
33. 33.⚡ What number does this code print?
    let a = 52;
    let b = 3;
    console.log(a + b);
34. 34.⚡ What number does this code print?
    let a = 34;
    let b = 8;
    console.log(a - b);
35. 35.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, Zoya! (b) Zoya (c) Hello, name! (d) name
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 8 (b) Error (c) 71
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 9;
    console.log(x + y); (a) 79 (b) Error (c) 16
38. 38.⚡ What number does this code print?
    let a = 33;
    let b = 14;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let marks = 26;
    marks = marks + 2;
    marks = marks - 11;
    console.log(marks);
40. 40.⚡ What number does this code print?
    let a = 31;
    let b = 9;
    console.log(a + b);

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