JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 86 · 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 print? (Look at the quotes!)
   let x = "6";
   let y = 3;
   console.log(x + y); (a) 9 (b) Error (c) 63
2. 2.⚡ Which JavaScript word repeats code? (a) alert() (b) for (c) if (d) console.log()
3. 3.⚡ What number does this code print?
   let score = 10;
   score = score + 10;
   score = score - 1;
   console.log(score);
4. 4.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 1;
   console.log(x + y); (a) 91 (b) 10 (c) Error
5. 5.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) console.log() (d) let
6. 6.⚡ What does this code show?
   let name = "Zoya";
   alert("Hi, " + name + "!"); (a) Hi, Zoya! (b) name (c) Zoya (d) Hi, name!
7. 7.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .jpg (d) .css
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 7;
   console.log(x + y); (a) Error (b) 8 (c) 17
9. 9.⚡ What number does this code print?
   let runs = 10;
   runs = runs + 18;
   runs = runs - 7;
   console.log(runs);
10. 10.⚡ Which word makes a new variable? (a) let (b) give (c) make (d) put
11. 11.⚡ Which JavaScript word makes a new variable? (a) let (b) for (c) console.log() (d) if
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 2;
    console.log(x + y); (a) 7 (b) Error (c) 52
13. 13.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) let (d) if
14. 14.⚡ What number does this code print?
    let a = 24;
    let b = 4;
    console.log(a - b);
15. 15.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hello, " + name + "!"); (a) Hello, Zoya! (b) name (c) Zoya (d) Hello, name!
16. 16.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) name (b) Welcome, Meera! (c) Meera (d) Welcome, name!
17. 17.⚡ What number does this code print?
    let a = 15;
    let b = 2;
    console.log(a + b);
18. 18.⚡ What number does this code print?
    let a = 16;
    let b = 35;
    console.log(a + b);
19. 19.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) name (c) Hello, Riya! (d) Hello, name!
20. 20.⚡ What does alert() show? (a) a new tab (b) a table (c) a pop-up box (d) a picture
21. 21.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <code> (c) <js> (d) <style>
22. 22.⚡ What does this code show?
    let name = "Riya";
    console.log("Hi, " + name + "!"); (a) name (b) Riya (c) Hi, name! (d) Hi, Riya!
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 85 (b) Error (c) 13
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 8;
    console.log(x + y); (a) Error (b) 88 (c) 16
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 4;
    console.log(x + y); (a) Error (b) 24 (c) 6
26. 26.⚡ Where does console.log() show its output? (a) in the console (b) on the printer (c) on the title bar (d) in the address bar
27. 27.⚡ What number does this code print?
    let marks = 12;
    marks = marks + 13;
    marks = marks - 10;
    console.log(marks);
28. 28.⚡ What number does this code print?
    let coins = 27;
    coins = coins + 13;
    coins = coins - 37;
    console.log(coins);
29. 29.⚡ What does this code show?
    let name = "Aman";
    console.log("Hi, " + name + "!"); (a) Aman (b) Hi, Aman! (c) Hi, name! (d) name
30. 30.⚡ Which JavaScript word shows a pop-up box? (a) let (b) if (c) for (d) alert()
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 3;
    console.log(x + y); (a) 53 (b) 8 (c) Error
32. 32.⚡ What number does this code print?
    let a = 56;
    let b = 35;
    console.log(a - b);
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 7;
    console.log(x + y); (a) Error (b) 57 (c) 12
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 6;
    console.log(x + y); (a) 12 (b) 66 (c) Error
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 5;
    console.log(x + y); (a) 45 (b) Error (c) 9
36. 36.⚡ What number does this code print?
    let a = 20;
    let b = 35;
    console.log(a + b);
37. 37.⚡ What number does this code print?
    let marks = 12;
    marks = marks + 18;
    marks = marks - 23;
    console.log(marks);
38. 38.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) actions and changes (d) only colours
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) 13 (b) 94 (c) Error
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) 97 (b) 16 (c) Error

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