JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 198 · 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 = 9;
   let b = 34;
   console.log(a + b);
2. 2.⚡ What number does this code print?
   let apples = 5;
   apples = apples + 6;
   apples = apples - 11;
   console.log(apples);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 6;
   console.log(x + y); (a) Error (b) 86 (c) 14
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 6;
   console.log(x + y); (a) Error (b) 13 (c) 76
5. 5.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .css (d) .html
6. 6.⚡ What number does this code print?
   let a = 20;
   let b = 2;
   console.log(a - b);
7. 7.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) let (d) console.log()
8. 8.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
9. 9.⚡ Which word makes a new variable? (a) let (b) give (c) make (d) put
10. 10.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) if (d) console.log()
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 19 (b) Error (c) 10
12. 12.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, name! (c) name (d) Hi, Arjun!
13. 13.⚡ Which JavaScript word writes in the console? (a) alert() (b) if (c) for (d) console.log()
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) Error (c) 35
15. 15.⚡ What number does this code print?
    let a = 28;
    let b = 22;
    console.log(a - b);
16. 16.⚡ What number does this code print?
    let a = 37;
    let b = 2;
    console.log(a + b);
17. 17.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Meera (b) Hello, Meera! (c) Hello, name! (d) name
18. 18.⚡ What number does this code print?
    let a = 26;
    let b = 6;
    console.log(a - b);
19. 19.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) Error (b) 11 (c) 92
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 1;
    console.log(x + y); (a) 11 (b) Error (c) 2
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) 17 (b) Error (c) 89
23. 23.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) Aman (c) name (d) Hello, name!
24. 24.⚡ What number does this code print?
    let apples = 16;
    apples = apples + 2;
    apples = apples - 9;
    console.log(apples);
25. 25.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Arjun (c) name (d) Well done, Arjun!
26. 26.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
27. 27.⚡ What does JavaScript add to a web page? (a) the page title (b) actions and changes (c) the domain name (d) only colours
28. 28.⚡ What number does this code print?
    let a = 29;
    let b = 4;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 53;
    let b = 23;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let score = 17;
    score = score + 12;
    score = score - 25;
    console.log(score);
31. 31.⚡ What number does this code print?
    let runs = 15;
    runs = runs + 20;
    runs = runs - 24;
    console.log(runs);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) Error (b) 12 (c) 3
33. 33.⚡ What number does this code print?
    let a = 51;
    let b = 34;
    console.log(a - b);
34. 34.⚡ What number does this code print?
    let a = 36;
    let b = 27;
    console.log(a - b);
35. 35.⚡ What number does this code print?
    let a = 21;
    let b = 13;
    console.log(a + b);
36. 36.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Hi, Zoya! (b) Zoya (c) name (d) Hi, name!
37. 37.⚡ What number does this code print?
    let a = 35;
    let b = 15;
    console.log(a - b);
38. 38.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, name! (d) Welcome, Aman!
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) Error (b) 10 (c) 64
40. 40.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 4;
    apples = apples - 9;
    console.log(apples);

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