JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 1 · 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 = 53;
   let b = 25;
   console.log(a - b);
2. 2.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) only colours (d) the page title
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) let (d) console.log()
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 4;
   console.log(x + y); (a) 8 (b) 44 (c) Error
5. 5.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
6. 6.⚡ What does alert() show? (a) a new tab (b) a pop-up box (c) a picture (d) a table
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 1;
   console.log(x + y); (a) 81 (b) Error (c) 9
8. 8.⚡ What does this code show?
   let name = "Aman";
   alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Aman (d) Hello, Aman!
9. 9.⚡ Which JavaScript word makes a new variable? (a) let (b) if (c) for (d) console.log()
10. 10.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) Welcome, name! (c) name (d) Zoya
11. 11.⚡ Which JavaScript word repeats code? (a) for (b) let (c) console.log() (d) alert()
12. 12.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console
13. 13.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Zoya (d) Hello, Zoya!
14. 14.⚡ 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
15. 15.⚡ Which JavaScript word writes in the console? (a) if (b) let (c) console.log() (d) for
16. 16.⚡ What number does this code print?
    let score = 15;
    score = score + 2;
    score = score - 4;
    console.log(score);
17. 17.⚡ What number does this code print?
    let a = 26;
    let b = 12;
    console.log(a - b);
18. 18.⚡ What number does this code print?
    let runs = 7;
    runs = runs + 7;
    runs = runs - 10;
    console.log(runs);
19. 19.⚡ Which JavaScript word runs code when true? (a) console.log() (b) let (c) if (d) alert()
20. 20.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, Kabir! (b) Kabir (c) Hello, name! (d) name
21. 21.⚡ What number does this code print?
    let a = 21;
    let b = 17;
    console.log(a + b);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) Error (b) 9 (c) 54
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) Error (b) 12 (c) 93
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) 13 (b) 49 (c) Error
25. 25.⚡ What number does this code print?
    let a = 16;
    let b = 27;
    console.log(a + b);
26. 26.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, Arjun! (b) name (c) Hi, name! (d) Arjun
27. 27.⚡ What number does this code print?
    let apples = 18;
    apples = apples + 16;
    apples = apples - 8;
    console.log(apples);
28. 28.⚡ What number does this code print?
    let coins = 15;
    coins = coins + 19;
    coins = coins - 25;
    console.log(coins);
29. 29.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Hi, Zoya! (c) Zoya (d) name
30. 30.⚡ What number does this code print?
    let a = 43;
    let b = 3;
    console.log(a + b);
31. 31.⚡ What number does this code print?
    let a = 54;
    let b = 7;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 14;
    coins = coins - 6;
    console.log(coins);
33. 33.⚡ Which word makes a new variable? (a) give (b) let (c) make (d) put
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 41 (c) 5
35. 35.⚡ What number does this code print?
    let a = 14;
    let b = 14;
    console.log(a + b);
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 19 (b) 10 (c) Error
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 4;
    console.log(x + y); (a) 74 (b) 11 (c) Error
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 7;
    console.log(x + y); (a) 47 (b) Error (c) 11
39. 39.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Aman! (c) Hi, name! (d) Aman
40. 40.⚡ 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

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