JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 887 · 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 = 21;
   let b = 5;
   console.log(a - b);
2. 2.⚡ What does this code show?
   let name = "Zoya";
   alert("Hello, " + name + "!"); (a) Zoya (b) Hello, Zoya! (c) Hello, name! (d) name
3. 3.⚡ Which JavaScript word runs code when true? (a) console.log() (b) for (c) if (d) alert()
4. 4.⚡ What number does this code print?
   let a = 13;
   let b = 10;
   console.log(a - b);
5. 5.⚡ What number does this code print?
   let coins = 8;
   coins = coins + 5;
   coins = coins - 7;
   console.log(coins);
6. 6.⚡ What number does this code print?
   let coins = 16;
   coins = coins + 17;
   coins = coins - 7;
   console.log(coins);
7. 7.⚡ What number does this code print?
   let runs = 12;
   runs = runs + 7;
   runs = runs - 15;
   console.log(runs);
8. 8.⚡ Which JavaScript word makes a new variable? (a) let (b) for (c) alert() (d) console.log()
9. 9.⚡ What does this code show?
   let name = "Riya";
   alert("Welcome, " + name + "!"); (a) Riya (b) name (c) Welcome, Riya! (d) Welcome, name!
10. 10.⚡ What number does this code print?
    let a = 17;
    let b = 5;
    console.log(a + b);
11. 11.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) name (b) Meera (c) Welcome, name! (d) Welcome, Meera!
12. 12.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) alert() (d) if
13. 13.⚡ Which JavaScript word repeats code? (a) alert() (b) if (c) for (d) let
14. 14.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) alert() (d) for
15. 15.⚡ Where does console.log() show its output? (a) in the console (b) on the title bar (c) in the address bar (d) on the printer
16. 16.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 3;
    console.log(x + y); (a) 83 (b) 11 (c) Error
17. 17.⚡ What number does this code print?
    let a = 10;
    let b = 12;
    console.log(a * b);
18. 18.⚡ What number does this code print?
    let a = 45;
    let b = 16;
    console.log(a - b);
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 8 (b) 71 (c) Error
20. 20.⚡ What number does this code print?
    let a = 15;
    let b = 18;
    console.log(a + b);
21. 21.⚡ What number does this code print?
    let a = 13;
    let b = 37;
    console.log(a + b);
22. 22.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
23. 23.⚡ What number does this code print?
    let apples = 8;
    apples = apples + 12;
    apples = apples - 12;
    console.log(apples);
24. 24.⚡ What does JavaScript add to a web page? (a) the page title (b) only colours (c) actions and changes (d) the domain name
25. 25.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, Riya! (b) Riya (c) name (d) Hi, name!
26. 26.⚡ What does this code show?
    let name = "Arjun";
    console.log("Well done, " + name + "!"); (a) Well done, Arjun! (b) Arjun (c) name (d) Well done, name!
27. 27.⚡ What number does this code print?
    let apples = 5;
    apples = apples + 19;
    apples = apples - 23;
    console.log(apples);
28. 28.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
29. 29.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) name (c) Kabir (d) Welcome, name!
30. 30.⚡ Which word makes a new variable? (a) make (b) give (c) let (d) put
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 6;
    console.log(x + y); (a) 9 (b) 36 (c) Error
32. 32.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Kabir (c) name (d) Hello, Kabir!
33. 33.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) name (d) Welcome, Arjun!
34. 34.⚡ What number does this code print?
    let a = 41;
    let b = 6;
    console.log(a + b);
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 6;
    console.log(x + y); (a) 11 (b) 56 (c) Error
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 7;
    console.log(x + y); (a) 14 (b) 77 (c) Error
37. 37.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
38. 38.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 3;
    console.log(x + y); (a) Error (b) 10 (c) 73
39. 39.⚡ What number does this code print?
    let a = 22;
    let b = 10;
    console.log(a - b);
40. 40.⚡ What number does this code print?
    let a = 18;
    let b = 31;
    console.log(a + b);

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