JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 589 · 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 a = 12;
   let b = 4;
   console.log(a - b);
2. 2.⚡ What number does this code print?
   let a = 11;
   let b = 6;
   console.log(a - b);
3. 3.⚡ What number does this code print?
   let a = 20;
   let b = 6;
   console.log(a + b);
4. 4.⚡ What does this code show?
   let name = "Aman";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Welcome, Aman! (d) Aman
5. 5.⚡ What number does this code print?
   let a = 42;
   let b = 5;
   console.log(a - b);
6. 6.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) the domain name (d) actions and changes
7. 7.⚡ What number does this code print?
   let a = 26;
   let b = 33;
   console.log(a + b);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 2;
   console.log(x + y); (a) Error (b) 9 (c) 72
9. 9.⚡ 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
10. 10.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) on the title bar (d) in the address bar
11. 11.⚡ What number does this code print?
    let score = 23;
    score = score + 9;
    score = score - 4;
    console.log(score);
12. 12.⚡ Which JavaScript word writes in the console? (a) console.log() (b) alert() (c) let (d) for
13. 13.⚡ What number does this code print?
    let marks = 23;
    marks = marks + 19;
    marks = marks - 2;
    console.log(marks);
14. 14.⚡ What number does this code print?
    let a = 47;
    let b = 16;
    console.log(a - b);
15. 15.⚡ Which JavaScript word runs code when true? (a) alert() (b) let (c) console.log() (d) if
16. 16.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <code> (d) <js>
17. 17.⚡ What number does this code print?
    let a = 4;
    let b = 4;
    console.log(a * b);
18. 18.⚡ What does this code show?
    let name = "Meera";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Meera (c) name (d) Hello, Meera!
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) Error (b) 62 (c) 8
20. 20.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hi, " + name + "!"); (a) Arjun (b) Hi, Arjun! (c) name (d) Hi, name!
21. 21.⚡ What number does this code print?
    let a = 46;
    let b = 10;
    console.log(a - b);
22. 22.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) 41 (b) 5 (c) Error
23. 23.⚡ What number does this code print?
    let runs = 25;
    runs = runs + 3;
    runs = runs - 19;
    console.log(runs);
24. 24.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) for (d) let
25. 25.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Zoya! (c) name (d) Zoya
26. 26.⚡ Which JavaScript word repeats code? (a) console.log() (b) alert() (c) for (d) if
27. 27.⚡ What number does this code print?
    let a = 51;
    let b = 1;
    console.log(a - b);
28. 28.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) for
29. 29.⚡ What does alert() show? (a) a pop-up box (b) a table (c) a picture (d) a new tab
30. 30.⚡ What number does this code print?
    let a = 10;
    let b = 2;
    console.log(a * b);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) Error (b) 8 (c) 44
32. 32.⚡ What number does this code print?
    let runs = 29;
    runs = runs + 6;
    runs = runs - 29;
    console.log(runs);
33. 33.⚡ What number does this code print?
    let a = 44;
    let b = 3;
    console.log(a - b);
34. 34.⚡ What number does this code print?
    let runs = 21;
    runs = runs + 8;
    runs = runs - 14;
    console.log(runs);
35. 35.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) Zoya (b) Hi, Zoya! (c) Hi, name! (d) name
36. 36.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Well done, Arjun! (d) Arjun
37. 37.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
38. 38.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Riya (b) Well done, name! (c) Well done, Riya! (d) name
39. 39.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .jpg (d) .js
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 22 (b) 4 (c) Error

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