JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 329 · 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 does this code print? (Look at the quotes!)
   let x = "2";
   let y = 4;
   console.log(x + y); (a) 24 (b) Error (c) 6
2. 2.⚡ What number does this code print?
   let a = 5;
   let b = 3;
   console.log(a * b);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 3;
   console.log(x + y); (a) 10 (b) 73 (c) Error
4. 4.⚡ What number does this code print?
   let runs = 11;
   runs = runs + 18;
   runs = runs - 9;
   console.log(runs);
5. 5.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) Hi, Arjun! (d) name
6. 6.⚡ Which JavaScript word runs code when true? (a) let (b) alert() (c) console.log() (d) if
7. 7.⚡ What does this code show?
   let name = "Arjun";
   console.log("Welcome, " + name + "!"); (a) name (b) Arjun (c) Welcome, name! (d) Welcome, Arjun!
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Arjun! (d) Arjun
9. 9.⚡ What number does this code print?
   let apples = 13;
   apples = apples + 14;
   apples = apples - 17;
   console.log(apples);
10. 10.⚡ What number does this code print?
    let a = 15;
    let b = 14;
    console.log(a - b);
11. 11.⚡ Which word makes a new variable? (a) put (b) let (c) give (d) make
12. 12.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, Zoya! (c) Zoya (d) Welcome, name!
13. 13.⚡ What number does this code print?
    let a = 17;
    let b = 37;
    console.log(a + b);
14. 14.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, name! (c) Hello, Meera! (d) Meera
15. 15.⚡ What number does this code print?
    let a = 30;
    let b = 27;
    console.log(a - b);
16. 16.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a new tab (d) a table
17. 17.⚡ What number does this code print?
    let a = 33;
    let b = 9;
    console.log(a + b);
18. 18.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) console.log() (d) let
19. 19.⚡ Which JavaScript word makes a new variable? (a) if (b) let (c) alert() (d) console.log()
20. 20.⚡ What number does this code print?
    let a = 43;
    let b = 7;
    console.log(a + b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 1;
    console.log(x + y); (a) 21 (b) 3 (c) Error
22. 22.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Riya (b) Welcome, Riya! (c) name (d) Welcome, name!
23. 23.⚡ What number does this code print?
    let a = 2;
    let b = 10;
    console.log(a * b);
24. 24.⚡ What number does this code print?
    let a = 40;
    let b = 18;
    console.log(a - b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) Error (b) 12 (c) 66
26. 26.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .css (d) .jpg
27. 27.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) on the printer (d) in the console
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 10 (b) Error (c) 19
29. 29.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, Riya! (d) Hi, name!
30. 30.⚡ What number does this code print?
    let a = 5;
    let b = 9;
    console.log(a * b);
31. 31.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, Riya! (b) Hello, name! (c) Riya (d) name
32. 32.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) alert() (d) console.log()
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 4;
    console.log(x + y); (a) 5 (b) Error (c) 14
34. 34.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Aman (b) name (c) Hello, name! (d) Hello, Aman!
35. 35.⚡ Which JavaScript word repeats code? (a) if (b) let (c) for (d) console.log()
36. 36.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
37. 37.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 7;
    apples = apples - 5;
    console.log(apples);
38. 38.⚡ What number does this code print?
    let apples = 13;
    apples = apples + 15;
    apples = apples - 8;
    console.log(apples);
39. 39.⚡ What number does this code print?
    let score = 24;
    score = score + 20;
    score = score - 20;
    console.log(score);
40. 40.⚡ What number does this code print?
    let books = 22;
    books = books + 5;
    books = books - 4;
    console.log(books);

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