JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 311 · 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 = "9";
   let y = 7;
   console.log(x + y); (a) Error (b) 97 (c) 16
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 2;
   console.log(x + y); (a) 12 (b) Error (c) 3
3. 3.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
4. 4.⚡ Which JavaScript word runs code when true? (a) for (b) alert() (c) if (d) console.log()
5. 5.⚡ Which JavaScript word makes a new variable? (a) alert() (b) for (c) let (d) if
6. 6.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 7;
   console.log(x + y); (a) 57 (b) 12 (c) Error
8. 8.⚡ Which word makes a new variable? (a) let (b) give (c) make (d) put
9. 9.⚡ What number does this code print?
   let coins = 28;
   coins = coins + 19;
   coins = coins - 42;
   console.log(coins);
10. 10.⚡ What number does this code print?
    let marks = 13;
    marks = marks + 11;
    marks = marks - 20;
    console.log(marks);
11. 11.⚡ What number does this code print?
    let a = 39;
    let b = 8;
    console.log(a - b);
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) 9 (b) 27 (c) Error
13. 13.⚡ What number does this code print?
    let books = 6;
    books = books + 9;
    books = books - 10;
    console.log(books);
14. 14.⚡ What number does this code print?
    let a = 2;
    let b = 9;
    console.log(a * b);
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 25 (b) 7 (c) Error
16. 16.⚡ 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
17. 17.⚡ What number does this code print?
    let a = 46;
    let b = 1;
    console.log(a - b);
18. 18.⚡ 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
19. 19.⚡ What does this code show?
    let name = "Kabir";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Well done, Kabir! (d) Kabir
20. 20.⚡ What number does this code print?
    let runs = 18;
    runs = runs + 4;
    runs = runs - 8;
    console.log(runs);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 9 (b) 45 (c) Error
22. 22.⚡ What number does this code print?
    let coins = 8;
    coins = coins + 8;
    coins = coins - 10;
    console.log(coins);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 6;
    console.log(x + y); (a) Error (b) 13 (c) 76
24. 24.⚡ Which JavaScript word writes in the console? (a) let (b) if (c) for (d) console.log()
25. 25.⚡ What does JavaScript add to a web page? (a) the page title (b) actions and changes (c) only colours (d) the domain name
26. 26.⚡ What number does this code print?
    let coins = 29;
    coins = coins + 10;
    coins = coins - 37;
    console.log(coins);
27. 27.⚡ What number does this code print?
    let a = 2;
    let b = 12;
    console.log(a * b);
28. 28.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Riya (d) Welcome, name!
29. 29.⚡ Which JavaScript word shows a pop-up box? (a) let (b) if (c) alert() (d) for
30. 30.⚡ What does alert() show? (a) a picture (b) a table (c) a new tab (d) a pop-up box
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) Error (b) 44 (c) 8
32. 32.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 9;
    apples = apples - 17;
    console.log(apples);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) 89 (b) Error (c) 17
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) Error (b) 72 (c) 9
35. 35.⚡ What number does this code print?
    let a = 11;
    let b = 26;
    console.log(a + b);
36. 36.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Kabir! (d) Kabir
37. 37.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, name! (b) Arjun (c) Well done, Arjun! (d) name
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 3;
    console.log(x + y); (a) 23 (b) Error (c) 5
39. 39.⚡ Which JavaScript word repeats code? (a) for (b) alert() (c) let (d) console.log()
40. 40.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Kabir (b) Hi, Kabir! (c) Hi, name! (d) name

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