JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 992 · 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 = 10;
   let b = 6;
   console.log(a - b);
2. 2.⚡ Which JavaScript word runs code when true? (a) if (b) let (c) console.log() (d) for
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 3;
   console.log(x + y); (a) 11 (b) 83 (c) Error
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 1;
   console.log(x + y); (a) Error (b) 2 (c) 11
5. 5.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) alert() (d) console.log()
6. 6.⚡ What number does this code print?
   let a = 60;
   let b = 27;
   console.log(a + b);
7. 7.⚡ What number does this code print?
   let a = 34;
   let b = 8;
   console.log(a - b);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "6";
   let y = 8;
   console.log(x + y); (a) Error (b) 14 (c) 68
9. 9.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .css (d) .js
10. 10.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a table (d) a picture
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) for (d) console.log()
12. 12.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 15;
    apples = apples - 33;
    console.log(apples);
13. 13.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Riya! (c) Riya (d) name
14. 14.⚡ What number does this code print?
    let a = 27;
    let b = 9;
    console.log(a - b);
15. 15.⚡ 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
16. 16.⚡ 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
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) Error (b) 92 (c) 11
18. 18.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Kabir (d) Hello, Kabir!
19. 19.⚡ Which word makes a new variable? (a) let (b) make (c) give (d) put
20. 20.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 17;
    apples = apples - 6;
    console.log(apples);
21. 21.⚡ What number does this code print?
    let runs = 28;
    runs = runs + 16;
    runs = runs - 44;
    console.log(runs);
22. 22.⚡ What number does this code print?
    let a = 46;
    let b = 31;
    console.log(a - b);
23. 23.⚡ 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
24. 24.⚡ What number does this code print?
    let a = 26;
    let b = 7;
    console.log(a - b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) Error (b) 43 (c) 7
26. 26.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) if (c) let (d) for
27. 27.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
28. 28.⚡ What number does this code print?
    let score = 17;
    score = score + 4;
    score = score - 11;
    console.log(score);
29. 29.⚡ What number does this code print?
    let a = 8;
    let b = 31;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let score = 10;
    score = score + 19;
    score = score - 28;
    console.log(score);
31. 31.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Arjun (b) Well done, name! (c) Well done, Arjun! (d) name
32. 32.⚡ What number does this code print?
    let a = 11;
    let b = 12;
    console.log(a * b);
33. 33.⚡ What number does this code print?
    let coins = 8;
    coins = coins + 8;
    coins = coins - 10;
    console.log(coins);
34. 34.⚡ Which JavaScript word repeats code? (a) alert() (b) if (c) console.log() (d) for
35. 35.⚡ What number does this code print?
    let a = 11;
    let b = 8;
    console.log(a - b);
36. 36.⚡ What number does this code print?
    let a = 31;
    let b = 32;
    console.log(a + b);
37. 37.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Hi, Arjun! (b) Hi, name! (c) name (d) Arjun
38. 38.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Aman (d) Welcome, Aman!
39. 39.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Hello, Riya! (b) Riya (c) name (d) Hello, name!
40. 40.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Aman (b) Hi, Aman! (c) Hi, name! (d) name

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