JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 417 · 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 = 1;
   console.log(x + y); (a) 21 (b) 3 (c) Error
2. 2.⚡ What does JavaScript add to a web page? (a) actions and changes (b) only colours (c) the domain name (d) the page title
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 6;
   console.log(x + y); (a) 36 (b) Error (c) 9
4. 4.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) let (d) for
5. 5.⚡ What number does this code print?
   let a = 55;
   let b = 6;
   console.log(a - b);
6. 6.⚡ What number does this code print?
   let a = 53;
   let b = 8;
   console.log(a + b);
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 6;
   console.log(x + y); (a) 10 (b) Error (c) 46
8. 8.⚡ What number does this code print?
   let a = 5;
   let b = 6;
   console.log(a * b);
9. 9.⚡ What number does this code print?
   let a = 7;
   let b = 6;
   console.log(a * b);
10. 10.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <code> (d) <script>
11. 11.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) let (d) alert()
12. 12.⚡ Which JavaScript word writes in the console? (a) alert() (b) if (c) let (d) console.log()
13. 13.⚡ Which JavaScript word makes a new variable? (a) for (b) console.log() (c) let (d) alert()
14. 14.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) in the console (d) on the printer
15. 15.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 4;
    apples = apples - 3;
    console.log(apples);
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) 12 (b) 39 (c) Error
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 9;
    console.log(x + y); (a) 17 (b) Error (c) 89
18. 18.⚡ What number does this code print?
    let a = 22;
    let b = 18;
    console.log(a - b);
19. 19.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .js (c) .jpg (d) .css
20. 20.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, Aman! (b) name (c) Aman (d) Well done, name!
21. 21.⚡ What number does this code print?
    let runs = 17;
    runs = runs + 12;
    runs = runs - 12;
    console.log(runs);
22. 22.⚡ What number does this code print?
    let a = 15;
    let b = 32;
    console.log(a + b);
23. 23.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Riya (b) Well done, Riya! (c) Well done, name! (d) name
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) Error (b) 8 (c) 53
25. 25.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Kabir (c) Welcome, Kabir! (d) name
26. 26.⚡ What number does this code print?
    let a = 10;
    let b = 5;
    console.log(a * b);
27. 27.⚡ What number does this code print?
    let apples = 27;
    apples = apples + 12;
    apples = apples - 10;
    console.log(apples);
28. 28.⚡ What number does this code print?
    let marks = 8;
    marks = marks + 18;
    marks = marks - 6;
    console.log(marks);
29. 29.⚡ What number does this code print?
    let a = 52;
    let b = 36;
    console.log(a - b);
30. 30.⚡ What does this code show?
    let name = "Zoya";
    console.log("Well done, " + name + "!"); (a) Zoya (b) Well done, Zoya! (c) name (d) Well done, name!
31. 31.⚡ What number does this code print?
    let a = 31;
    let b = 1;
    console.log(a - b);
32. 32.⚡ What number does this code print?
    let a = 52;
    let b = 23;
    console.log(a + b);
33. 33.⚡ What number does this code print?
    let a = 56;
    let b = 23;
    console.log(a + b);
34. 34.⚡ What number does this code print?
    let a = 6;
    let b = 12;
    console.log(a * b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) 8 (b) 17 (c) Error
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 71 (b) Error (c) 8
37. 37.⚡ What number does this code print?
    let a = 6;
    let b = 9;
    console.log(a * b);
38. 38.⚡ What number does this code print?
    let a = 5;
    let b = 4;
    console.log(a * b);
39. 39.⚡ What number does this code print?
    let a = 33;
    let b = 19;
    console.log(a - b);
40. 40.⚡ What does this code show?
    let name = "Riya";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Riya (c) name (d) Welcome, Riya!

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