JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 27 · 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.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 9;
   console.log(x + y); (a) Error (b) 89 (c) 17
3. 3.⚡ What does this code show?
   let name = "Kabir";
   console.log("Well done, " + name + "!"); (a) Well done, Kabir! (b) name (c) Kabir (d) Well done, name!
4. 4.⚡ What number does this code print?
   let a = 21;
   let b = 12;
   console.log(a + b);
5. 5.⚡ What number does this code print?
   let apples = 6;
   apples = apples + 12;
   apples = apples - 3;
   console.log(apples);
6. 6.⚡ What does this code show?
   let name = "Riya";
   console.log("Well done, " + name + "!"); (a) Well done, Riya! (b) name (c) Riya (d) Well done, name!
7. 7.⚡ Which word makes a new variable? (a) make (b) give (c) let (d) put
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 3;
   console.log(x + y); (a) 73 (b) 10 (c) Error
9. 9.⚡ What number does this code print?
   let score = 10;
   score = score + 13;
   score = score - 1;
   console.log(score);
10. 10.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
11. 11.⚡ What number does this code print?
    let apples = 9;
    apples = apples + 16;
    apples = apples - 10;
    console.log(apples);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 9 (b) 36 (c) Error
13. 13.⚡ Which JavaScript word makes a new variable? (a) for (b) alert() (c) let (d) if
14. 14.⚡ What does alert() show? (a) a picture (b) a table (c) a new tab (d) a pop-up box
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) 6 (b) Error (c) 51
16. 16.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 20;
    runs = runs - 4;
    console.log(runs);
17. 17.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Aman (c) Welcome, Aman! (d) name
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) 35 (c) Error
19. 19.⚡ Which JavaScript word writes in the console? (a) alert() (b) for (c) console.log() (d) if
20. 20.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) let (d) for
21. 21.⚡ Which JavaScript word repeats code? (a) alert() (b) let (c) for (d) console.log()
22. 22.⚡ What number does this code print?
    let a = 36;
    let b = 34;
    console.log(a + b);
23. 23.⚡ What number does this code print?
    let a = 38;
    let b = 10;
    console.log(a + b);
24. 24.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) let (d) console.log()
25. 25.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Kabir (c) Welcome, Kabir! (d) name
26. 26.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) Hello, Riya! (c) Hello, name! (d) name
27. 27.⚡ 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
28. 28.⚡ What does this code show?
    let name = "Zoya";
    alert("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) Zoya (c) Welcome, name! (d) name
29. 29.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 5;
    apples = apples - 25;
    console.log(apples);
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) Error (b) 27 (c) 9
31. 31.⚡ What number does this code print?
    let a = 5;
    let b = 8;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let a = 9;
    let b = 11;
    console.log(a + b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 5;
    console.log(x + y); (a) 55 (b) Error (c) 10
34. 34.⚡ What number does this code print?
    let a = 24;
    let b = 31;
    console.log(a + b);
35. 35.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) name (b) Aman (c) Hi, name! (d) Hi, Aman!
36. 36.⚡ Where does console.log() show its output? (a) in the console (b) in the address bar (c) on the title bar (d) on the printer
37. 37.⚡ What number does this code print?
    let a = 26;
    let b = 19;
    console.log(a - b);
38. 38.⚡ What number does this code print?
    let a = 11;
    let b = 11;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let books = 11;
    books = books + 5;
    books = books - 1;
    console.log(books);
40. 40.⚡ What number does this code print?
    let runs = 21;
    runs = runs + 20;
    runs = runs - 28;
    console.log(runs);

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