JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 943 · 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 show?
   let name = "Meera";
   alert("Hello, " + name + "!"); (a) Meera (b) name (c) Hello, Meera! (d) Hello, name!
2. 2.⚡ What number does this code print?
   let runs = 28;
   runs = runs + 16;
   runs = runs - 17;
   console.log(runs);
3. 3.⚡ Which JavaScript word writes in the console? (a) console.log() (b) let (c) alert() (d) for
4. 4.⚡ What does alert() show? (a) a pop-up box (b) a table (c) a new tab (d) a picture
5. 5.⚡ What number does this code print?
   let score = 18;
   score = score + 16;
   score = score - 6;
   console.log(score);
6. 6.⚡ What number does this code print?
   let a = 47;
   let b = 33;
   console.log(a - b);
7. 7.⚡ Which JavaScript word makes a new variable? (a) for (b) if (c) console.log() (d) let
8. 8.⚡ What does JavaScript add to a web page? (a) the domain name (b) actions and changes (c) only colours (d) the page title
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 7;
   console.log(x + y); (a) 12 (b) 57 (c) Error
10. 10.⚡ 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
11. 11.⚡ Which JavaScript word shows a pop-up box? (a) let (b) console.log() (c) alert() (d) for
12. 12.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Zoya! (b) Zoya (c) name (d) Welcome, name!
13. 13.⚡ What number does this code print?
    let a = 56;
    let b = 4;
    console.log(a + b);
14. 14.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
15. 15.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .jpg (d) .css
16. 16.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) let (d) alert()
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) Error (b) 12 (c) 93
18. 18.⚡ What number does this code print?
    let a = 32;
    let b = 26;
    console.log(a - b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 31 (c) 4
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 4;
    console.log(x + y); (a) Error (b) 74 (c) 11
21. 21.⚡ Which JavaScript word repeats code? (a) for (b) if (c) console.log() (d) alert()
22. 22.⚡ What number does this code print?
    let a = 10;
    let b = 12;
    console.log(a * b);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 8;
    console.log(x + y); (a) 38 (b) 11 (c) Error
24. 24.⚡ What number does this code print?
    let a = 49;
    let b = 7;
    console.log(a - b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 9;
    console.log(x + y); (a) 99 (b) 18 (c) Error
26. 26.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Hi, Meera! (d) Meera
27. 27.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 16;
    runs = runs - 2;
    console.log(runs);
28. 28.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
29. 29.⚡ What number does this code print?
    let coins = 23;
    coins = coins + 4;
    coins = coins - 27;
    console.log(coins);
30. 30.⚡ What number does this code print?
    let marks = 7;
    marks = marks + 20;
    marks = marks - 21;
    console.log(marks);
31. 31.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Meera (b) Well done, Meera! (c) Well done, name! (d) name
32. 32.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) in the console (d) on the printer
33. 33.⚡ What number does this code print?
    let a = 10;
    let b = 7;
    console.log(a * b);
34. 34.⚡ 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
35. 35.⚡ What number does this code print?
    let a = 4;
    let b = 8;
    console.log(a * b);
36. 36.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, Kabir! (b) Kabir (c) Hi, name! (d) name
37. 37.⚡ What number does this code print?
    let a = 14;
    let b = 4;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let a = 47;
    let b = 36;
    console.log(a - b);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) 11 (b) Error (c) 56
40. 40.⚡ What number does this code print?
    let a = 60;
    let b = 16;
    console.log(a + b);

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