JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 559 · 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 number does this code print?
   let apples = 21;
   apples = apples + 4;
   apples = apples - 21;
   console.log(apples);
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) alert() (c) for (d) let
3. 3.⚡ Which word makes a new variable? (a) give (b) make (c) let (d) put
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 2;
   console.log(x + y); (a) 11 (b) Error (c) 92
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 5;
   console.log(x + y); (a) 15 (b) Error (c) 6
6. 6.⚡ What does JavaScript add to a web page? (a) only colours (b) actions and changes (c) the domain name (d) the page title
7. 7.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Riya (d) Welcome, name!
8. 8.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
9. 9.⚡ What number does this code print?
   let runs = 7;
   runs = runs + 5;
   runs = runs - 2;
   console.log(runs);
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 9 (b) Error (c) 36
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) Error (c) 35
12. 12.⚡ Which JavaScript word runs code when true? (a) console.log() (b) if (c) alert() (d) for
13. 13.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <js> (c) <code> (d) <style>
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) Error (b) 8 (c) 17
15. 15.⚡ What number does this code print?
    let a = 2;
    let b = 2;
    console.log(a * b);
16. 16.⚡ What number does this code print?
    let a = 21;
    let b = 12;
    console.log(a - b);
17. 17.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) Riya (b) Well done, Riya! (c) Well done, name! (d) name
18. 18.⚡ 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
19. 19.⚡ What number does this code print?
    let a = 11;
    let b = 5;
    console.log(a * b);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) Error (b) 11 (c) 65
21. 21.⚡ What number does this code print?
    let a = 13;
    let b = 39;
    console.log(a + b);
22. 22.⚡ What number does this code print?
    let a = 41;
    let b = 23;
    console.log(a + b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) Error (b) 22 (c) 4
24. 24.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a - b);
25. 25.⚡ What number does this code print?
    let a = 5;
    let b = 22;
    console.log(a + b);
26. 26.⚡ What number does this code print?
    let a = 43;
    let b = 39;
    console.log(a - b);
27. 27.⚡ What number does this code print?
    let a = 40;
    let b = 5;
    console.log(a + b);
28. 28.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 7;
    console.log(x + y); (a) Error (b) 67 (c) 13
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 41 (c) 5
30. 30.⚡ What number does this code print?
    let marks = 30;
    marks = marks + 18;
    marks = marks - 21;
    console.log(marks);
31. 31.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) Hello, Kabir! (d) name
32. 32.⚡ Which JavaScript word writes in the console? (a) for (b) let (c) console.log() (d) if
33. 33.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) name (b) Hello, Riya! (c) Riya (d) Hello, name!
34. 34.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) if (d) let
35. 35.⚡ What number does this code print?
    let a = 7;
    let b = 6;
    console.log(a * b);
36. 36.⚡ What number does this code print?
    let a = 30;
    let b = 6;
    console.log(a - b);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 8;
    console.log(x + y); (a) 98 (b) Error (c) 17
38. 38.⚡ What number does this code print?
    let a = 19;
    let b = 11;
    console.log(a - b);
39. 39.⚡ What number does this code print?
    let a = 14;
    let b = 5;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let score = 11;
    score = score + 5;
    score = score - 3;
    console.log(score);

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