JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 568 · 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.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) let (d) alert()
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 2;
   console.log(x + y); (a) Error (b) 82 (c) 10
3. 3.⚡ What number does this code print?
   let runs = 25;
   runs = runs + 14;
   runs = runs - 11;
   console.log(runs);
4. 4.⚡ What number does this code print?
   let a = 17;
   let b = 31;
   console.log(a + b);
5. 5.⚡ What does alert() show? (a) a table (b) a new tab (c) a picture (d) a pop-up box
6. 6.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .jpg (d) .html
7. 7.⚡ What number does this code print?
   let marks = 14;
   marks = marks + 4;
   marks = marks - 4;
   console.log(marks);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 5;
   console.log(x + y); (a) 14 (b) 95 (c) Error
9. 9.⚡ What number does this code print?
   let a = 32;
   let b = 8;
   console.log(a - b);
10. 10.⚡ What number does this code print?
    let a = 51;
    let b = 26;
    console.log(a - b);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) Error (b) 54 (c) 9
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) 15 (b) Error (c) 69
13. 13.⚡ Which JavaScript word makes a new variable? (a) console.log() (b) let (c) for (d) alert()
14. 14.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
15. 15.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the console (d) in the address bar
16. 16.⚡ What number does this code print?
    let a = 9;
    let b = 5;
    console.log(a * b);
17. 17.⚡ What number does this code print?
    let a = 9;
    let b = 10;
    console.log(a * b);
18. 18.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) let (d) console.log()
19. 19.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) for (d) if
20. 20.⚡ What number does this code print?
    let books = 30;
    books = books + 9;
    books = books - 31;
    console.log(books);
21. 21.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Zoya! (d) Zoya
22. 22.⚡ What number does this code print?
    let a = 4;
    let b = 7;
    console.log(a * b);
23. 23.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Zoya! (c) Zoya (d) Welcome, name!
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 3;
    console.log(x + y); (a) Error (b) 13 (c) 4
25. 25.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) name (b) Well done, Riya! (c) Riya (d) Well done, name!
26. 26.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) alert() (d) for
27. 27.⚡ What number does this code print?
    let a = 3;
    let b = 4;
    console.log(a * b);
28. 28.⚡ What number does this code print?
    let a = 5;
    let b = 10;
    console.log(a * b);
29. 29.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) name (b) Aman (c) Hello, name! (d) Hello, Aman!
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 22 (b) 4 (c) Error
31. 31.⚡ What number does this code print?
    let a = 44;
    let b = 30;
    console.log(a + b);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) 89 (b) 17 (c) Error
33. 33.⚡ What does this code show?
    let name = "Zoya";
    alert("Hello, " + name + "!"); (a) Zoya (b) name (c) Hello, name! (d) Hello, Zoya!
34. 34.⚡ What number does this code print?
    let a = 4;
    let b = 2;
    console.log(a * b);
35. 35.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
36. 36.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Aman (b) Hi, Aman! (c) name (d) Hi, name!
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 10 (b) 64 (c) Error
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) 12 (b) 39 (c) Error
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 18 (b) 99 (c) Error
40. 40.⚡ What number does this code print?
    let runs = 25;
    runs = runs + 19;
    runs = runs - 26;
    console.log(runs);

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