JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 595 · 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.⚡ Which JavaScript word writes in the console? (a) console.log() (b) if (c) let (d) alert()
2. 2.⚡ Which JavaScript word runs code when true? (a) alert() (b) console.log() (c) let (d) if
3. 3.⚡ What number does this code print?
   let runs = 7;
   runs = runs + 2;
   runs = runs - 9;
   console.log(runs);
4. 4.⚡ Which word makes a new variable? (a) give (b) put (c) make (d) let
5. 5.⚡ What number does this code print?
   let marks = 29;
   marks = marks + 6;
   marks = marks - 3;
   console.log(marks);
6. 6.⚡ Where does console.log() show its output? (a) on the printer (b) in the console (c) in the address bar (d) on the title bar
7. 7.⚡ A JavaScript file usually ends with which extension? (a) .jpg (b) .html (c) .js (d) .css
8. 8.⚡ What number does this code print?
   let a = 7;
   let b = 34;
   console.log(a + b);
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 7;
   console.log(x + y); (a) 27 (b) Error (c) 9
10. 10.⚡ What number does this code print?
    let a = 8;
    let b = 4;
    console.log(a * b);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) Error (b) 85 (c) 13
12. 12.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Welcome, Arjun! (b) name (c) Welcome, name! (d) Arjun
13. 13.⚡ Which JavaScript word makes a new variable? (a) for (b) console.log() (c) if (d) let
14. 14.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) name (b) Zoya (c) Hi, Zoya! (d) Hi, name!
15. 15.⚡ What number does this code print?
    let a = 49;
    let b = 21;
    console.log(a + b);
16. 16.⚡ What does alert() show? (a) a new tab (b) a picture (c) a table (d) a pop-up box
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 94 (b) Error (c) 13
18. 18.⚡ Which JavaScript word repeats code? (a) for (b) alert() (c) if (d) let
19. 19.⚡ What number does this code print?
    let a = 9;
    let b = 8;
    console.log(a * b);
20. 20.⚡ What number does this code print?
    let a = 30;
    let b = 2;
    console.log(a - b);
21. 21.⚡ Which JavaScript word shows a pop-up box? (a) if (b) console.log() (c) alert() (d) let
22. 22.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) Well done, Riya! (b) Riya (c) name (d) Well done, name!
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 5;
    console.log(x + y); (a) 25 (b) 7 (c) Error
24. 24.⚡ What does this code show?
    let name = "Meera";
    console.log("Well done, " + name + "!"); (a) name (b) Meera (c) Well done, name! (d) Well done, Meera!
25. 25.⚡ What does JavaScript add to a web page? (a) only colours (b) the page title (c) actions and changes (d) the domain name
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) Error (b) 9 (c) 54
27. 27.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) Zoya (c) Hello, Zoya! (d) name
28. 28.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) name (c) Meera (d) Well done, Meera!
29. 29.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 35 (b) Error (c) 8
30. 30.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <code> (d) <script>
31. 31.⚡ What number does this code print?
    let a = 4;
    let b = 12;
    console.log(a * b);
32. 32.⚡ What number does this code print?
    let a = 2;
    let b = 4;
    console.log(a * b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) 8 (b) 62 (c) Error
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 8;
    console.log(x + y); (a) 10 (b) Error (c) 28
35. 35.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Aman! (c) name (d) Aman
36. 36.⚡ What number does this code print?
    let marks = 14;
    marks = marks + 10;
    marks = marks - 23;
    console.log(marks);
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) 66 (b) 12 (c) Error
38. 38.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) Hello, Kabir! (d) name
39. 39.⚡ What number does this code print?
    let apples = 23;
    apples = apples + 12;
    apples = apples - 15;
    console.log(apples);
40. 40.⚡ What number does this code print?
    let coins = 20;
    coins = coins + 6;
    coins = coins - 15;
    console.log(coins);

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