JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 621 · 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 runs code when true? (a) let (b) alert() (c) if (d) for
2. 2.⚡ What does this code show?
   let name = "Meera";
   alert("Hello, " + name + "!"); (a) Hello, Meera! (b) name (c) Meera (d) Hello, name!
3. 3.⚡ What number does this code print?
   let a = 13;
   let b = 32;
   console.log(a + b);
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 7;
   console.log(x + y); (a) Error (b) 97 (c) 16
5. 5.⚡ What number does this code print?
   let a = 58;
   let b = 16;
   console.log(a + b);
6. 6.⚡ 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
7. 7.⚡ What number does this code print?
   let a = 20;
   let b = 17;
   console.log(a + b);
8. 8.⚡ What does this code show?
   let name = "Kabir";
   alert("Well done, " + name + "!"); (a) Kabir (b) Well done, name! (c) Well done, Kabir! (d) name
9. 9.⚡ Which word makes a new variable? (a) make (b) let (c) put (d) give
10. 10.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <code> (d) <style>
11. 11.⚡ Which JavaScript word writes in the console? (a) for (b) let (c) alert() (d) console.log()
12. 12.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) name (c) Hello, name! (d) Hello, Riya!
13. 13.⚡ 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
14. 14.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, Aman! (b) Aman (c) name (d) Welcome, name!
15. 15.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .css (d) .jpg
16. 16.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) for (d) console.log()
17. 17.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Riya (b) name (c) Hi, name! (d) Hi, Riya!
18. 18.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Riya! (d) Riya
19. 19.⚡ What number does this code print?
    let a = 4;
    let b = 5;
    console.log(a * b);
20. 20.⚡ Which JavaScript word makes a new variable? (a) for (b) console.log() (c) let (d) alert()
21. 21.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, Kabir! (c) name (d) Hello, name!
22. 22.⚡ Which JavaScript word repeats code? (a) for (b) if (c) console.log() (d) alert()
23. 23.⚡ What number does this code print?
    let a = 32;
    let b = 20;
    console.log(a + b);
24. 24.⚡ What number does this code print?
    let a = 29;
    let b = 13;
    console.log(a - b);
25. 25.⚡ What number does this code print?
    let a = 57;
    let b = 29;
    console.log(a - b);
26. 26.⚡ What does this code show?
    let name = "Aman";
    console.log("Hello, " + name + "!"); (a) Hello, Aman! (b) Aman (c) name (d) Hello, name!
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) 6 (b) 42 (c) Error
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) Error (b) 10 (c) 46
29. 29.⚡ What number does this code print?
    let a = 38;
    let b = 11;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let a = 25;
    let b = 9;
    console.log(a - b);
31. 31.⚡ What number does this code print?
    let a = 46;
    let b = 8;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let coins = 15;
    coins = coins + 20;
    coins = coins - 1;
    console.log(coins);
33. 33.⚡ What does this code show?
    let name = "Meera";
    console.log("Hi, " + name + "!"); (a) Hi, name! (b) Meera (c) name (d) Hi, Meera!
34. 34.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) name (d) Arjun
35. 35.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
36. 36.⚡ What number does this code print?
    let a = 35;
    let b = 27;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let marks = 15;
    marks = marks + 4;
    marks = marks - 7;
    console.log(marks);
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 1;
    console.log(x + y); (a) Error (b) 91 (c) 10
39. 39.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 5;
    apples = apples - 12;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let a = 9;
    let b = 1;
    console.log(a + b);

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