JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 408 · 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 does this code print? (Look at the quotes!)
   let x = "8";
   let y = 2;
   console.log(x + y); (a) 82 (b) Error (c) 10
2. 2.⚡ What number does this code print?
   let score = 14;
   score = score + 4;
   score = score - 1;
   console.log(score);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 7;
   console.log(x + y); (a) 15 (b) Error (c) 87
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 5;
   console.log(x + y); (a) 15 (b) 6 (c) Error
5. 5.⚡ What does alert() show? (a) a pop-up box (b) a table (c) a picture (d) a new tab
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
7. 7.⚡ What does this code show?
   let name = "Arjun";
   console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Arjun (d) Well done, Arjun!
8. 8.⚡ What number does this code print?
   let a = 10;
   let b = 2;
   console.log(a + b);
9. 9.⚡ What does this code show?
   let name = "Riya";
   alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Riya! (d) Riya
10. 10.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Arjun (c) name (d) Well done, Arjun!
11. 11.⚡ What number does this code print?
    let score = 8;
    score = score + 4;
    score = score - 12;
    console.log(score);
12. 12.⚡ What number does this code print?
    let a = 4;
    let b = 2;
    console.log(a * b);
13. 13.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <script> (c) <js> (d) <style>
14. 14.⚡ Which JavaScript word writes in the console? (a) console.log() (b) alert() (c) for (d) let
15. 15.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, Riya! (b) Riya (c) Hello, name! (d) name
16. 16.⚡ What number does this code print?
    let marks = 9;
    marks = marks + 19;
    marks = marks - 19;
    console.log(marks);
17. 17.⚡ Which word makes a new variable? (a) put (b) give (c) let (d) make
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) 6 (b) Error (c) 42
19. 19.⚡ What number does this code print?
    let a = 14;
    let b = 15;
    console.log(a + b);
20. 20.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) console.log() (d) let
21. 21.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) for (d) console.log()
22. 22.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Aman (b) Hi, Aman! (c) Hi, name! (d) name
23. 23.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) if (d) for
24. 24.⚡ What number does this code print?
    let marks = 27;
    marks = marks + 12;
    marks = marks - 32;
    console.log(marks);
25. 25.⚡ What number does this code print?
    let score = 23;
    score = score + 3;
    score = score - 16;
    console.log(score);
26. 26.⚡ What number does this code print?
    let a = 6;
    let b = 8;
    console.log(a * b);
27. 27.⚡ What number does this code print?
    let a = 10;
    let b = 4;
    console.log(a * b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) Error (b) 19 (c) 10
29. 29.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 10;
    apples = apples - 19;
    console.log(apples);
30. 30.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 3;
    apples = apples - 2;
    console.log(apples);
31. 31.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
32. 32.⚡ What number does this code print?
    let a = 21;
    let b = 18;
    console.log(a + b);
33. 33.⚡ What number does this code print?
    let a = 31;
    let b = 29;
    console.log(a + b);
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) 55 (b) 10 (c) Error
35. 35.⚡ What number does this code print?
    let runs = 7;
    runs = runs + 6;
    runs = runs - 1;
    console.log(runs);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 8 (b) Error (c) 53
37. 37.⚡ What number does this code print?
    let runs = 14;
    runs = runs + 19;
    runs = runs - 33;
    console.log(runs);
38. 38.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 3;
    apples = apples - 6;
    console.log(apples);
39. 39.⚡ What number does this code print?
    let a = 7;
    let b = 8;
    console.log(a * b);
40. 40.⚡ Where does console.log() show its output? (a) on the printer (b) on the title bar (c) in the address bar (d) in the console

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