JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 461 · 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 makes a new variable? (a) if (b) let (c) for (d) console.log()
2. 2.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Riya (c) Welcome, Riya! (d) name
3. 3.⚡ What does this code show?
   let name = "Aman";
   alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Aman! (d) Aman
4. 4.⚡ What number does this code print?
   let a = 20;
   let b = 9;
   console.log(a - b);
5. 5.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Arjun (d) Hello, Arjun!
6. 6.⚡ What does this code show?
   let name = "Zoya";
   alert("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) name (c) Zoya (d) Welcome, name!
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 7;
   console.log(x + y); (a) 37 (b) 10 (c) Error
8. 8.⚡ What does this code show?
   let name = "Meera";
   alert("Welcome, " + name + "!"); (a) name (b) Welcome, Meera! (c) Meera (d) Welcome, name!
9. 9.⚡ Which word makes a new variable? (a) put (b) give (c) make (d) let
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 7 (b) Error (c) 52
11. 11.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Kabir! (d) Kabir
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) 6 (b) Error (c) 24
13. 13.⚡ What number does this code print?
    let marks = 21;
    marks = marks + 5;
    marks = marks - 8;
    console.log(marks);
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) Error (b) 12 (c) 39
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 35 (b) Error (c) 8
16. 16.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Aman (c) Welcome, Aman! (d) Welcome, name!
17. 17.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Kabir! (c) Kabir (d) Hello, name!
18. 18.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Riya (c) Hello, name! (d) Hello, Riya!
19. 19.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 16 (b) Error (c) 97
21. 21.⚡ What number does this code print?
    let a = 9;
    let b = 7;
    console.log(a * b);
22. 22.⚡ Where does console.log() show its output? (a) in the address bar (b) on the printer (c) on the title bar (d) in the console
23. 23.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
24. 24.⚡ What number does this code print?
    let coins = 5;
    coins = coins + 8;
    coins = coins - 3;
    console.log(coins);
25. 25.⚡ Which JavaScript word writes in the console? (a) alert() (b) let (c) if (d) console.log()
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 2;
    console.log(x + y); (a) 3 (b) Error (c) 12
27. 27.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) for (d) console.log()
28. 28.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) let (d) console.log()
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) 91 (b) Error (c) 10
30. 30.⚡ What does this code show?
    let name = "Arjun";
    alert("Hi, " + name + "!"); (a) Arjun (b) Hi, name! (c) name (d) Hi, Arjun!
31. 31.⚡ What number does this code print?
    let a = 35;
    let b = 16;
    console.log(a - b);
32. 32.⚡ What number does this code print?
    let a = 9;
    let b = 3;
    console.log(a * b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 93 (b) 12 (c) Error
34. 34.⚡ What number does this code print?
    let a = 18;
    let b = 11;
    console.log(a + b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 2;
    console.log(x + y); (a) 92 (b) 11 (c) Error
36. 36.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, Aman! (c) Aman (d) Well done, name!
37. 37.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a picture (d) a new tab
38. 38.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 2;
    apples = apples - 24;
    console.log(apples);
39. 39.⚡ What number does this code print?
    let coins = 13;
    coins = coins + 11;
    coins = coins - 14;
    console.log(coins);
40. 40.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <js> (d) <script>

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