JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 275 · 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 = "4";
   let y = 2;
   console.log(x + y); (a) Error (b) 42 (c) 6
2. 2.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .js (c) .html (d) .jpg
3. 3.⚡ What number does this code print?
   let a = 46;
   let b = 20;
   console.log(a - b);
4. 4.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
5. 5.⚡ What number does this code print?
   let a = 3;
   let b = 9;
   console.log(a * b);
6. 6.⚡ Which JavaScript word repeats code? (a) let (b) console.log() (c) for (d) alert()
7. 7.⚡ What number does this code print?
   let coins = 22;
   coins = coins + 7;
   coins = coins - 21;
   console.log(coins);
8. 8.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) Welcome, Meera! (b) name (c) Meera (d) Welcome, name!
9. 9.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the title bar (d) on the printer
10. 10.⚡ What number does this code print?
    let score = 22;
    score = score + 20;
    score = score - 28;
    console.log(score);
11. 11.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) alert() (d) for
12. 12.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Aman (b) Welcome, Aman! (c) name (d) Welcome, name!
13. 13.⚡ What number does this code print?
    let a = 45;
    let b = 31;
    console.log(a + b);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) Error (b) 3 (c) 21
15. 15.⚡ What number does this code print?
    let a = 8;
    let b = 8;
    console.log(a + b);
16. 16.⚡ What number does this code print?
    let books = 6;
    books = books + 4;
    books = books - 5;
    console.log(books);
17. 17.⚡ What number does this code print?
    let a = 48;
    let b = 4;
    console.log(a + b);
18. 18.⚡ What number does this code print?
    let a = 5;
    let b = 3;
    console.log(a * b);
19. 19.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Riya (d) Hello, Riya!
20. 20.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Zoya! (c) Zoya (d) name
21. 21.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Hi, Kabir! (b) Hi, name! (c) name (d) Kabir
22. 22.⚡ What number does this code print?
    let a = 34;
    let b = 9;
    console.log(a + b);
23. 23.⚡ Which JavaScript word shows a pop-up box? (a) let (b) alert() (c) if (d) console.log()
24. 24.⚡ What number does this code print?
    let a = 9;
    let b = 2;
    console.log(a * b);
25. 25.⚡ What number does this code print?
    let apples = 15;
    apples = apples + 12;
    apples = apples - 1;
    console.log(apples);
26. 26.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) Aman (b) name (c) Well done, Aman! (d) Well done, name!
27. 27.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) alert()
28. 28.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) for (d) console.log()
29. 29.⚡ What number does this code print?
    let runs = 23;
    runs = runs + 16;
    runs = runs - 8;
    console.log(runs);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 78 (b) 15 (c) Error
31. 31.⚡ What number does this code print?
    let a = 40;
    let b = 14;
    console.log(a - b);
32. 32.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Aman (c) name (d) Welcome, Aman!
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 9 (b) Error (c) 45
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) name (b) Aman (c) Well done, Aman! (d) Well done, name!
35. 35.⚡ What number does this code print?
    let a = 35;
    let b = 36;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let a = 13;
    let b = 11;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let coins = 22;
    coins = coins + 9;
    coins = coins - 12;
    console.log(coins);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 6;
    console.log(x + y); (a) 86 (b) Error (c) 14
39. 39.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) Zoya (b) Hi, Zoya! (c) name (d) Hi, name!
40. 40.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) name

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