JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 362 · 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 alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
2. 2.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
3. 3.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) in the console (d) on the title bar
4. 4.⚡ What number does this code print?
   let a = 10;
   let b = 5;
   console.log(a * b);
5. 5.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) alert() (d) console.log()
6. 6.⚡ What number does this code print?
   let a = 6;
   let b = 20;
   console.log(a + b);
7. 7.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Riya! (c) Riya (d) name
8. 8.⚡ Which JavaScript word writes in the console? (a) alert() (b) console.log() (c) if (d) let
9. 9.⚡ What number does this code print?
   let books = 19;
   books = books + 6;
   books = books - 14;
   console.log(books);
10. 10.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) Welcome, name! (c) Kabir (d) name
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) Error (c) 13
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) if (d) let
13. 13.⚡ What number does this code print?
    let a = 7;
    let b = 8;
    console.log(a * b);
14. 14.⚡ What number does this code print?
    let runs = 27;
    runs = runs + 6;
    runs = runs - 5;
    console.log(runs);
15. 15.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, Meera! (b) Meera (c) Welcome, name! (d) name
16. 16.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Kabir! (d) Kabir
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 9;
    console.log(x + y); (a) 16 (b) Error (c) 79
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 6;
    console.log(x + y); (a) 7 (b) Error (c) 16
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 44 (b) Error (c) 8
20. 20.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Meera (d) Well done, Meera!
21. 21.⚡ What number does this code print?
    let coins = 12;
    coins = coins + 4;
    coins = coins - 9;
    console.log(coins);
22. 22.⚡ 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
23. 23.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) actions and changes (d) the page title
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 8;
    console.log(x + y); (a) 11 (b) 38 (c) Error
25. 25.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) name (d) Hi, Arjun!
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 35 (b) Error (c) 8
27. 27.⚡ What number does this code print?
    let a = 34;
    let b = 13;
    console.log(a - b);
28. 28.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Zoya (b) Hi, Zoya! (c) Hi, name! (d) name
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) 76 (b) Error (c) 13
30. 30.⚡ What number does this code print?
    let marks = 29;
    marks = marks + 16;
    marks = marks - 25;
    console.log(marks);
31. 31.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) name (d) Hello, Meera!
32. 32.⚡ What number does this code print?
    let apples = 26;
    apples = apples + 13;
    apples = apples - 4;
    console.log(apples);
33. 33.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Riya (b) Welcome, name! (c) Welcome, Riya! (d) name
34. 34.⚡ What number does this code print?
    let runs = 12;
    runs = runs + 2;
    runs = runs - 11;
    console.log(runs);
35. 35.⚡ What number does this code print?
    let a = 2;
    let b = 9;
    console.log(a * b);
36. 36.⚡ Which JavaScript word repeats code? (a) let (b) if (c) for (d) console.log()
37. 37.⚡ What number does this code print?
    let score = 23;
    score = score + 9;
    score = score - 8;
    console.log(score);
38. 38.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) console.log() (d) let
39. 39.⚡ What number does this code print?
    let score = 23;
    score = score + 6;
    score = score - 19;
    console.log(score);
40. 40.⚡ What number does this code print?
    let apples = 18;
    apples = apples + 7;
    apples = apples - 23;
    console.log(apples);

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