JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 289 · 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) for (b) if (c) let (d) console.log()
2. 2.⚡ What number does this code print?
   let a = 10;
   let b = 2;
   console.log(a * b);
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 1;
   console.log(x + y); (a) Error (b) 41 (c) 5
4. 4.⚡ What does this code show?
   let name = "Zoya";
   console.log("Hello, " + name + "!"); (a) name (b) Hello, Zoya! (c) Hello, name! (d) Zoya
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 5;
   console.log(x + y); (a) Error (b) 45 (c) 9
6. 6.⚡ What does this code show?
   let name = "Aman";
   console.log("Welcome, " + name + "!"); (a) Aman (b) Welcome, Aman! (c) Welcome, name! (d) name
7. 7.⚡ What number does this code print?
   let marks = 29;
   marks = marks + 18;
   marks = marks - 38;
   console.log(marks);
8. 8.⚡ What number does this code print?
   let score = 10;
   score = score + 12;
   score = score - 4;
   console.log(score);
9. 9.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) in the address bar (d) on the title bar
10. 10.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) console.log() (d) alert()
11. 11.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .js (d) .jpg
12. 12.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) the page title (d) actions and changes
13. 13.⚡ What does this code show?
    let name = "Zoya";
    alert("Hi, " + name + "!"); (a) name (b) Zoya (c) Hi, name! (d) Hi, Zoya!
14. 14.⚡ 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
15. 15.⚡ What number does this code print?
    let a = 6;
    let b = 4;
    console.log(a * b);
16. 16.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Kabir (d) Welcome, Kabir!
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 1;
    console.log(x + y); (a) Error (b) 4 (c) 31
18. 18.⚡ Which JavaScript word runs code when true? (a) for (b) alert() (c) if (d) console.log()
19. 19.⚡ What number does this code print?
    let a = 60;
    let b = 6;
    console.log(a - b);
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) Error (b) 9 (c) 72
21. 21.⚡ What number does this code print?
    let a = 58;
    let b = 33;
    console.log(a - b);
22. 22.⚡ Which word makes a new variable? (a) give (b) make (c) let (d) put
23. 23.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <js> (c) <style> (d) <code>
24. 24.⚡ What number does this code print?
    let apples = 21;
    apples = apples + 18;
    apples = apples - 13;
    console.log(apples);
25. 25.⚡ What number does this code print?
    let coins = 8;
    coins = coins + 16;
    coins = coins - 23;
    console.log(coins);
26. 26.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Meera! (c) Welcome, name! (d) Meera
27. 27.⚡ What does this code show?
    let name = "Riya";
    console.log("Well done, " + name + "!"); (a) name (b) Riya (c) Well done, Riya! (d) Well done, name!
28. 28.⚡ What number does this code print?
    let marks = 24;
    marks = marks + 2;
    marks = marks - 4;
    console.log(marks);
29. 29.⚡ What does this code show?
    let name = "Meera";
    console.log("Welcome, " + name + "!"); (a) Welcome, Meera! (b) Meera (c) name (d) Welcome, name!
30. 30.⚡ Which JavaScript word makes a new variable? (a) alert() (b) if (c) for (d) let
31. 31.⚡ What number does this code print?
    let runs = 27;
    runs = runs + 3;
    runs = runs - 13;
    console.log(runs);
32. 32.⚡ What number does this code print?
    let a = 12;
    let b = 4;
    console.log(a * b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) 58 (b) 13 (c) Error
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 1;
    console.log(x + y); (a) 8 (b) Error (c) 71
35. 35.⚡ Which JavaScript word repeats code? (a) let (b) console.log() (c) for (d) if
36. 36.⚡ What number does this code print?
    let a = 21;
    let b = 6;
    console.log(a - b);
37. 37.⚡ What number does this code print?
    let a = 29;
    let b = 16;
    console.log(a - b);
38. 38.⚡ What number does this code print?
    let a = 41;
    let b = 3;
    console.log(a + b);
39. 39.⚡ What number does this code print?
    let apples = 6;
    apples = apples + 12;
    apples = apples - 11;
    console.log(apples);
40. 40.⚡ What does alert() show? (a) a picture (b) a pop-up box (c) a table (d) a new tab

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