JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 347 · 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 = 8;
   let b = 12;
   console.log(a * b);
2. 2.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) for (c) console.log() (d) if
3. 3.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <script> (c) <code> (d) <js>
4. 4.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .js (c) .jpg (d) .html
5. 5.⚡ What number does this code print?
   let runs = 7;
   runs = runs + 10;
   runs = runs - 5;
   console.log(runs);
6. 6.⚡ What does this code show?
   let name = "Zoya";
   alert("Hi, " + name + "!"); (a) Zoya (b) Hi, Zoya! (c) Hi, name! (d) name
7. 7.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the page title (c) the domain name (d) only colours
8. 8.⚡ What does alert() show? (a) a new tab (b) a table (c) a picture (d) a pop-up box
9. 9.⚡ Which JavaScript word writes in the console? (a) let (b) console.log() (c) alert() (d) for
10. 10.⚡ Which word makes a new variable? (a) give (b) let (c) make (d) put
11. 11.⚡ What number does this code print?
    let runs = 18;
    runs = runs + 2;
    runs = runs - 20;
    console.log(runs);
12. 12.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, Aman! (b) Hello, name! (c) Aman (d) name
13. 13.⚡ What number does this code print?
    let a = 4;
    let b = 2;
    console.log(a * b);
14. 14.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) console.log() (d) let
15. 15.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 6;
    console.log(x + y); (a) Error (b) 7 (c) 16
16. 16.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) alert() (d) if
17. 17.⚡ What number does this code print?
    let a = 52;
    let b = 26;
    console.log(a - b);
18. 18.⚡ What number does this code print?
    let a = 40;
    let b = 33;
    console.log(a - b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 7;
    console.log(x + y); (a) Error (b) 27 (c) 9
20. 20.⚡ Where does console.log() show its output? (a) in the address bar (b) on the title bar (c) on the printer (d) in the console
21. 21.⚡ What number does this code print?
    let a = 40;
    let b = 23;
    console.log(a - b);
22. 22.⚡ What number does this code print?
    let coins = 27;
    coins = coins + 15;
    coins = coins - 14;
    console.log(coins);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 7 (b) Error (c) 25
24. 24.⚡ What number does this code print?
    let a = 44;
    let b = 24;
    console.log(a + b);
25. 25.⚡ What number does this code print?
    let coins = 9;
    coins = coins + 19;
    coins = coins - 11;
    console.log(coins);
26. 26.⚡ What number does this code print?
    let a = 22;
    let b = 6;
    console.log(a - b);
27. 27.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Aman (c) Welcome, Aman! (d) name
28. 28.⚡ What number does this code print?
    let a = 22;
    let b = 11;
    console.log(a - b);
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 8;
    console.log(x + y); (a) 15 (b) 78 (c) Error
30. 30.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) Error (b) 49 (c) 13
31. 31.⚡ What number does this code print?
    let coins = 21;
    coins = coins + 10;
    coins = coins - 10;
    console.log(coins);
32. 32.⚡ Which JavaScript word repeats code? (a) for (b) let (c) if (d) alert()
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) Error (b) 7 (c) 43
34. 34.⚡ 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
35. 35.⚡ What number does this code print?
    let a = 22;
    let b = 38;
    console.log(a + b);
36. 36.⚡ What number does this code print?
    let a = 19;
    let b = 9;
    console.log(a - b);
37. 37.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) name (d) Hi, Kabir!
38. 38.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) name (b) Hi, Riya! (c) Hi, name! (d) Riya
39. 39.⚡ What number does this code print?
    let a = 51;
    let b = 17;
    console.log(a - b);
40. 40.⚡ What number does this code print?
    let a = 5;
    let b = 19;
    console.log(a + b);

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