JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 890 · 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 = "1";
   let y = 2;
   console.log(x + y); (a) 3 (b) Error (c) 12
2. 2.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 2;
   console.log(x + y); (a) Error (b) 92 (c) 11
3. 3.⚡ Which tag holds JavaScript in a page? (a) <js> (b) <script> (c) <code> (d) <style>
4. 4.⚡ What does this code show?
   let name = "Aman";
   alert("Hi, " + name + "!"); (a) name (b) Aman (c) Hi, Aman! (d) Hi, name!
5. 5.⚡ What number does this code print?
   let a = 13;
   let b = 9;
   console.log(a + b);
6. 6.⚡ Where does console.log() show its output? (a) on the title bar (b) in the address bar (c) on the printer (d) in the console
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "8";
   let y = 2;
   console.log(x + y); (a) 82 (b) Error (c) 10
8. 8.⚡ Which JavaScript word shows a pop-up box? (a) for (b) alert() (c) console.log() (d) let
9. 9.⚡ Which word makes a new variable? (a) make (b) put (c) give (d) let
10. 10.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Meera (b) Welcome, Meera! (c) name (d) Welcome, name!
11. 11.⚡ What does this code show?
    let name = "Arjun";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Arjun (d) Welcome, Arjun!
12. 12.⚡ What does alert() show? (a) a table (b) a pop-up box (c) a new tab (d) a picture
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 9;
    console.log(x + y); (a) Error (b) 69 (c) 15
14. 14.⚡ What number does this code print?
    let score = 26;
    score = score + 13;
    score = score - 33;
    console.log(score);
15. 15.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) for (d) if
16. 16.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) console.log() (d) for
17. 17.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, Kabir! (c) Hello, name! (d) name
18. 18.⚡ What number does this code print?
    let marks = 17;
    marks = marks + 8;
    marks = marks - 4;
    console.log(marks);
19. 19.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) let (d) for
20. 20.⚡ What number does this code print?
    let runs = 17;
    runs = runs + 5;
    runs = runs - 3;
    console.log(runs);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) 26 (b) 8 (c) Error
22. 22.⚡ What number does this code print?
    let a = 7;
    let b = 11;
    console.log(a * b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) Error (b) 66 (c) 12
24. 24.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .js (c) .css (d) .html
25. 25.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
26. 26.⚡ What number does this code print?
    let a = 18;
    let b = 12;
    console.log(a - b);
27. 27.⚡ What number does this code print?
    let marks = 16;
    marks = marks + 16;
    marks = marks - 29;
    console.log(marks);
28. 28.⚡ 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
29. 29.⚡ What number does this code print?
    let a = 30;
    let b = 16;
    console.log(a - b);
30. 30.⚡ Which JavaScript word writes in the console? (a) for (b) console.log() (c) alert() (d) if
31. 31.⚡ What number does this code print?
    let score = 25;
    score = score + 16;
    score = score - 24;
    console.log(score);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) Error (b) 88 (c) 16
33. 33.⚡ 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
34. 34.⚡ What number does this code print?
    let apples = 8;
    apples = apples + 5;
    apples = apples - 3;
    console.log(apples);
35. 35.⚡ What number does this code print?
    let runs = 5;
    runs = runs + 2;
    runs = runs - 2;
    console.log(runs);
36. 36.⚡ What number does this code print?
    let a = 3;
    let b = 10;
    console.log(a * b);
37. 37.⚡ What number does this code print?
    let score = 7;
    score = score + 11;
    score = score - 9;
    console.log(score);
38. 38.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Meera! (d) Meera
39. 39.⚡ What number does this code print?
    let a = 23;
    let b = 3;
    console.log(a + b);
40. 40.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) name

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