JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 997 · 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 show?
   let name = "Arjun";
   alert("Hi, " + name + "!"); (a) Hi, name! (b) Arjun (c) name (d) Hi, Arjun!
2. 2.⚡ Which word makes a new variable? (a) let (b) put (c) give (d) make
3. 3.⚡ What number does this code print?
   let apples = 27;
   apples = apples + 9;
   apples = apples - 31;
   console.log(apples);
4. 4.⚡ Which JavaScript word makes a new variable? (a) for (b) console.log() (c) let (d) alert()
5. 5.⚡ What does this code print? (Look at the quotes!)
   let x = "4";
   let y = 1;
   console.log(x + y); (a) Error (b) 5 (c) 41
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "2";
   let y = 7;
   console.log(x + y); (a) 9 (b) 27 (c) Error
7. 7.⚡ Which JavaScript word writes in the console? (a) let (b) console.log() (c) if (d) for
8. 8.⚡ Which JavaScript word runs code when true? (a) if (b) console.log() (c) for (d) alert()
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "3";
   let y = 1;
   console.log(x + y); (a) 4 (b) 31 (c) Error
10. 10.⚡ What number does this code print?
    let score = 10;
    score = score + 19;
    score = score - 2;
    console.log(score);
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 2;
    console.log(x + y); (a) 5 (b) 32 (c) Error
12. 12.⚡ Where does console.log() show its output? (a) in the address bar (b) in the console (c) on the title bar (d) on the printer
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 3;
    console.log(x + y); (a) 43 (b) Error (c) 7
14. 14.⚡ What does this code show?
    let name = "Riya";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Riya (c) Well done, Riya! (d) name
15. 15.⚡ What does JavaScript add to a web page? (a) the domain name (b) only colours (c) the page title (d) actions and changes
16. 16.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .html (c) .jpg (d) .js
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 5;
    console.log(x + y); (a) 8 (b) 35 (c) Error
18. 18.⚡ Which JavaScript word repeats code? (a) if (b) alert() (c) console.log() (d) for
19. 19.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Kabir (b) Welcome, Kabir! (c) Welcome, name! (d) name
20. 20.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) 84 (b) 12 (c) Error
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) Error (b) 44 (c) 8
22. 22.⚡ What does this code show?
    let name = "Zoya";
    alert("Well done, " + name + "!"); (a) Zoya (b) Well done, Zoya! (c) name (d) Well done, name!
23. 23.⚡ What number does this code print?
    let a = 47;
    let b = 28;
    console.log(a - b);
24. 24.⚡ What number does this code print?
    let a = 9;
    let b = 6;
    console.log(a + b);
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 5;
    console.log(x + y); (a) 13 (b) Error (c) 85
26. 26.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) name (b) Aman (c) Hello, Aman! (d) Hello, name!
27. 27.⚡ What number does this code print?
    let a = 12;
    let b = 6;
    console.log(a * b);
28. 28.⚡ What does alert() show? (a) a table (b) a new tab (c) a pop-up box (d) a picture
29. 29.⚡ What number does this code print?
    let runs = 29;
    runs = runs + 13;
    runs = runs - 32;
    console.log(runs);
30. 30.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 15;
    apples = apples - 19;
    console.log(apples);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 4;
    console.log(x + y); (a) 54 (b) Error (c) 9
32. 32.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Kabir! (c) name (d) Kabir
33. 33.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 4;
    console.log(x + y); (a) 10 (b) Error (c) 64
34. 34.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) console.log() (c) let (d) if
35. 35.⚡ What number does this code print?
    let a = 16;
    let b = 22;
    console.log(a + b);
36. 36.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <js> (c) <style> (d) <script>
37. 37.⚡ What number does this code print?
    let a = 2;
    let b = 12;
    console.log(a * b);
38. 38.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) Hello, name! (c) name (d) Hello, Riya!
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 4;
    console.log(x + y); (a) Error (b) 34 (c) 7
40. 40.⚡ What number does this code print?
    let a = 7;
    let b = 4;
    console.log(a * b);

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