JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 917 · 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 = "2";
   let y = 2;
   console.log(x + y); (a) Error (b) 4 (c) 22
2. 2.⚡ 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
3. 3.⚡ What does alert() show? (a) a picture (b) a new tab (c) a pop-up box (d) a table
4. 4.⚡ 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
5. 5.⚡ Which JavaScript word writes in the console? (a) if (b) let (c) console.log() (d) alert()
6. 6.⚡ Which JavaScript word repeats code? (a) let (b) if (c) console.log() (d) for
7. 7.⚡ What number does this code print?
   let marks = 26;
   marks = marks + 16;
   marks = marks - 35;
   console.log(marks);
8. 8.⚡ What number does this code print?
   let a = 22;
   let b = 40;
   console.log(a + b);
9. 9.⚡ What number does this code print?
   let a = 54;
   let b = 31;
   console.log(a + b);
10. 10.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 6;
    console.log(x + y); (a) Error (b) 96 (c) 15
11. 11.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 8;
    console.log(x + y); (a) 13 (b) Error (c) 58
12. 12.⚡ Which word makes a new variable? (a) put (b) make (c) give (d) let
13. 13.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) Aman (b) Hi, Aman! (c) name (d) Hi, name!
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 4;
    console.log(x + y); (a) Error (b) 13 (c) 94
15. 15.⚡ What number does this code print?
    let a = 21;
    let b = 39;
    console.log(a + b);
16. 16.⚡ What does this code show?
    let name = "Kabir";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Kabir (c) Hi, Kabir! (d) name
17. 17.⚡ What number does this code print?
    let a = 4;
    let b = 11;
    console.log(a * b);
18. 18.⚡ Which tag holds JavaScript in a page? (a) <script> (b) <style> (c) <code> (d) <js>
19. 19.⚡ What number does this code print?
    let runs = 6;
    runs = runs + 2;
    runs = runs - 2;
    console.log(runs);
20. 20.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) alert() (d) console.log()
21. 21.⚡ What does this code show?
    let name = "Arjun";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Arjun (c) Welcome, Arjun! (d) name
22. 22.⚡ What number does this code print?
    let a = 6;
    let b = 1;
    console.log(a - b);
23. 23.⚡ What number does this code print?
    let a = 12;
    let b = 37;
    console.log(a + b);
24. 24.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 6;
    console.log(x + y); (a) Error (b) 10 (c) 46
25. 25.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 2;
    console.log(x + y); (a) 42 (b) Error (c) 6
26. 26.⚡ Which JavaScript word makes a new variable? (a) alert() (b) console.log() (c) if (d) let
27. 27.⚡ A JavaScript file usually ends with which extension? (a) .html (b) .css (c) .jpg (d) .js
28. 28.⚡ What number does this code print?
    let apples = 25;
    apples = apples + 13;
    apples = apples - 2;
    console.log(apples);
29. 29.⚡ What number does this code print?
    let a = 57;
    let b = 5;
    console.log(a + b);
30. 30.⚡ What number does this code print?
    let a = 12;
    let b = 8;
    console.log(a * b);
31. 31.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Kabir! (c) Kabir (d) Hi, name!
32. 32.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, Riya! (b) name (c) Riya (d) Welcome, name!
33. 33.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Zoya (b) name (c) Welcome, Zoya! (d) Welcome, name!
34. 34.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 1;
    console.log(x + y); (a) 6 (b) 51 (c) Error
35. 35.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) 62 (b) Error (c) 8
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "7";
    let y = 2;
    console.log(x + y); (a) 9 (b) Error (c) 72
37. 37.⚡ What number does this code print?
    let a = 20;
    let b = 5;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let a = 39;
    let b = 7;
    console.log(a + b);
39. 39.⚡ What number does this code print?
    let a = 23;
    let b = 24;
    console.log(a + b);
40. 40.⚡ What number does this code print?
    let a = 12;
    let b = 8;
    console.log(a - b);

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