JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 869 · 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 alert() show? (a) a new tab (b) a picture (c) a pop-up box (d) a table
2. 2.⚡ What does this code show?
   let name = "Kabir";
   console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) name (c) Kabir (d) Welcome, Kabir!
3. 3.⚡ What number does this code print?
   let runs = 5;
   runs = runs + 6;
   runs = runs - 1;
   console.log(runs);
4. 4.⚡ What does this code show?
   let name = "Meera";
   console.log("Welcome, " + name + "!"); (a) Welcome, Meera! (b) Meera (c) name (d) Welcome, name!
5. 5.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Arjun (b) name (c) Hi, Arjun! (d) Hi, name!
6. 6.⚡ 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
7. 7.⚡ Which JavaScript word makes a new variable? (a) let (b) console.log() (c) alert() (d) for
8. 8.⚡ What number does this code print?
   let a = 34;
   let b = 3;
   console.log(a - b);
9. 9.⚡ What number does this code print?
   let a = 55;
   let b = 20;
   console.log(a + b);
10. 10.⚡ Which word makes a new variable? (a) let (b) give (c) make (d) put
11. 11.⚡ Which JavaScript word runs code when true? (a) if (b) for (c) let (d) alert()
12. 12.⚡ What number does this code print?
    let a = 28;
    let b = 10;
    console.log(a - b);
13. 13.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) let (c) for (d) console.log()
14. 14.⚡ What number does this code print?
    let a = 37;
    let b = 26;
    console.log(a + b);
15. 15.⚡ What number does this code print?
    let coins = 14;
    coins = coins + 19;
    coins = coins - 7;
    console.log(coins);
16. 16.⚡ What does this code show?
    let name = "Kabir";
    alert("Hello, " + name + "!"); (a) Hello, Kabir! (b) Kabir (c) name (d) Hello, name!
17. 17.⚡ What does this code show?
    let name = "Arjun";
    alert("Well done, " + name + "!"); (a) Well done, name! (b) Well done, Arjun! (c) Arjun (d) name
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 3;
    console.log(x + y); (a) Error (b) 6 (c) 33
19. 19.⚡ What does this code print? (Look at the quotes!)
    let x = "5";
    let y = 9;
    console.log(x + y); (a) 14 (b) Error (c) 59
20. 20.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the address bar (d) in the console
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 5;
    console.log(x + y); (a) Error (b) 11 (c) 65
22. 22.⚡ What number does this code print?
    let a = 33;
    let b = 38;
    console.log(a + b);
23. 23.⚡ What does this code show?
    let name = "Arjun";
    console.log("Hello, " + name + "!"); (a) Arjun (b) Hello, name! (c) name (d) Hello, Arjun!
24. 24.⚡ What number does this code print?
    let a = 9;
    let b = 9;
    console.log(a * b);
25. 25.⚡ What does this code show?
    let name = "Aman";
    console.log("Well done, " + name + "!"); (a) name (b) Well done, name! (c) Aman (d) Well done, Aman!
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 3;
    console.log(x + y); (a) 93 (b) 12 (c) Error
27. 27.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 7;
    console.log(x + y); (a) Error (b) 16 (c) 97
28. 28.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
29. 29.⚡ Which JavaScript word writes in the console? (a) for (b) if (c) console.log() (d) let
30. 30.⚡ What number does this code print?
    let coins = 9;
    coins = coins + 5;
    coins = coins - 4;
    console.log(coins);
31. 31.⚡ What number does this code print?
    let a = 13;
    let b = 12;
    console.log(a + b);
32. 32.⚡ What number does this code print?
    let a = 7;
    let b = 8;
    console.log(a * b);
33. 33.⚡ What number does this code print?
    let a = 19;
    let b = 7;
    console.log(a - b);
34. 34.⚡ Which JavaScript word repeats code? (a) alert() (b) console.log() (c) for (d) if
35. 35.⚡ What number does this code print?
    let apples = 22;
    apples = apples + 10;
    apples = apples - 30;
    console.log(apples);
36. 36.⚡ What does JavaScript add to a web page? (a) the page title (b) the domain name (c) only colours (d) actions and changes
37. 37.⚡ What number does this code print?
    let coins = 8;
    coins = coins + 11;
    coins = coins - 6;
    console.log(coins);
38. 38.⚡ What number does this code print?
    let apples = 29;
    apples = apples + 13;
    apples = apples - 23;
    console.log(apples);
39. 39.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 4;
    console.log(x + y); (a) 8 (b) 44 (c) Error
40. 40.⚡ What number does this code print?
    let a = 38;
    let b = 36;
    console.log(a - b);

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