JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 36 · 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.⚡ 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
2. 2.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
3. 3.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) alert() (d) let
4. 4.⚡ Which JavaScript word shows a pop-up box? (a) console.log() (b) for (c) let (d) alert()
5. 5.⚡ What number does this code print?
   let a = 15;
   let b = 11;
   console.log(a - b);
6. 6.⚡ Which word makes a new variable? (a) put (b) give (c) make (d) let
7. 7.⚡ What number does this code print?
   let a = 20;
   let b = 9;
   console.log(a - b);
8. 8.⚡ What number does this code print?
   let a = 5;
   let b = 19;
   console.log(a + b);
9. 9.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) for (d) if
10. 10.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) Welcome, name! (c) Kabir (d) name
11. 11.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <js> (c) <script> (d) <code>
12. 12.⚡ What number does this code print?
    let coins = 28;
    coins = coins + 9;
    coins = coins - 36;
    console.log(coins);
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 7;
    console.log(x + y); (a) 8 (b) 17 (c) Error
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) 13 (b) Error (c) 49
15. 15.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Kabir (b) Hello, name! (c) name (d) Hello, Kabir!
16. 16.⚡ What number does this code print?
    let runs = 30;
    runs = runs + 7;
    runs = runs - 10;
    console.log(runs);
17. 17.⚡ What number does this code print?
    let a = 48;
    let b = 32;
    console.log(a + b);
18. 18.⚡ What number does this code print?
    let apples = 30;
    apples = apples + 4;
    apples = apples - 10;
    console.log(apples);
19. 19.⚡ A JavaScript file usually ends with which extension? (a) .css (b) .jpg (c) .js (d) .html
20. 20.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 18;
    apples = apples - 5;
    console.log(apples);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) Error (b) 22 (c) 4
22. 22.⚡ What number does this code print?
    let score = 29;
    score = score + 12;
    score = score - 23;
    console.log(score);
23. 23.⚡ What number does this code print?
    let a = 51;
    let b = 1;
    console.log(a - b);
24. 24.⚡ What does this code show?
    let name = "Meera";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) Meera (c) Hi, Meera! (d) name
25. 25.⚡ What does this code show?
    let name = "Zoya";
    console.log("Hi, " + name + "!"); (a) name (b) Hi, Zoya! (c) Hi, name! (d) Zoya
26. 26.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, Aman! (c) Aman (d) Welcome, name!
27. 27.⚡ Which JavaScript word runs code when true? (a) console.log() (b) alert() (c) let (d) if
28. 28.⚡ What number does this code print?
    let a = 37;
    let b = 36;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 56;
    let b = 22;
    console.log(a - b);
30. 30.⚡ What number does this code print?
    let coins = 16;
    coins = coins + 12;
    coins = coins - 4;
    console.log(coins);
31. 31.⚡ What number does this code print?
    let a = 58;
    let b = 21;
    console.log(a + b);
32. 32.⚡ What does JavaScript add to a web page? (a) only colours (b) the domain name (c) the page title (d) actions and changes
33. 33.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Arjun (b) Well done, Arjun! (c) name (d) Well done, name!
34. 34.⚡ Which JavaScript word repeats code? (a) console.log() (b) alert() (c) for (d) if
35. 35.⚡ What number does this code print?
    let runs = 8;
    runs = runs + 5;
    runs = runs - 5;
    console.log(runs);
36. 36.⚡ What does this code show?
    let name = "Riya";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Riya! (d) Riya
37. 37.⚡ What number does this code print?
    let a = 35;
    let b = 39;
    console.log(a + b);
38. 38.⚡ What number does this code print?
    let coins = 6;
    coins = coins + 6;
    coins = coins - 9;
    console.log(coins);
39. 39.⚡ What number does this code print?
    let runs = 9;
    runs = runs + 13;
    runs = runs - 8;
    console.log(runs);
40. 40.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) 11 (b) Error (c) 65

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