JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 245 · 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 = "3";
   let y = 2;
   console.log(x + y); (a) Error (b) 32 (c) 5
2. 2.⚡ What number does this code print?
   let marks = 15;
   marks = marks + 16;
   marks = marks - 14;
   console.log(marks);
3. 3.⚡ Which JavaScript word shows a pop-up box? (a) if (b) alert() (c) for (d) console.log()
4. 4.⚡ What number does this code print?
   let a = 56;
   let b = 2;
   console.log(a + b);
5. 5.⚡ What does alert() show? (a) a table (b) a picture (c) a pop-up box (d) a new tab
6. 6.⚡ What does this code print? (Look at the quotes!)
   let x = "5";
   let y = 2;
   console.log(x + y); (a) Error (b) 52 (c) 7
7. 7.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 7;
   console.log(x + y); (a) Error (b) 77 (c) 14
8. 8.⚡ Which word makes a new variable? (a) let (b) make (c) give (d) put
9. 9.⚡ What does this code print? (Look at the quotes!)
   let x = "9";
   let y = 2;
   console.log(x + y); (a) 11 (b) Error (c) 92
10. 10.⚡ What does this code show?
    let name = "Riya";
    console.log("Hello, " + name + "!"); (a) Riya (b) Hello, name! (c) Hello, Riya! (d) name
11. 11.⚡ What does JavaScript add to a web page? (a) the domain name (b) the page title (c) only colours (d) actions and changes
12. 12.⚡ What does this code show?
    let name = "Kabir";
    console.log("Hi, " + name + "!"); (a) Hi, Kabir! (b) Kabir (c) name (d) Hi, name!
13. 13.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .css (c) .jpg (d) .html
14. 14.⚡ What number does this code print?
    let runs = 20;
    runs = runs + 2;
    runs = runs - 22;
    console.log(runs);
15. 15.⚡ What does this code show?
    let name = "Aman";
    alert("Well done, " + name + "!"); (a) Well done, Aman! (b) Aman (c) name (d) Well done, name!
16. 16.⚡ What number does this code print?
    let runs = 22;
    runs = runs + 17;
    runs = runs - 15;
    console.log(runs);
17. 17.⚡ What does this code print? (Look at the quotes!)
    let x = "3";
    let y = 9;
    console.log(x + y); (a) Error (b) 12 (c) 39
18. 18.⚡ What number does this code print?
    let score = 29;
    score = score + 4;
    score = score - 27;
    console.log(score);
19. 19.⚡ What number does this code print?
    let marks = 27;
    marks = marks + 10;
    marks = marks - 7;
    console.log(marks);
20. 20.⚡ Which JavaScript word writes in the console? (a) alert() (b) for (c) let (d) console.log()
21. 21.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Aman! (c) Aman (d) name
22. 22.⚡ What number does this code print?
    let a = 20;
    let b = 20;
    console.log(a - b);
23. 23.⚡ What number does this code print?
    let a = 21;
    let b = 2;
    console.log(a - b);
24. 24.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) for
25. 25.⚡ What number does this code print?
    let score = 23;
    score = score + 2;
    score = score - 17;
    console.log(score);
26. 26.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 2;
    console.log(x + y); (a) Error (b) 8 (c) 62
27. 27.⚡ What does this code show?
    let name = "Riya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Riya! (c) name (d) Riya
28. 28.⚡ What does this code show?
    let name = "Meera";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Meera! (c) Meera (d) name
29. 29.⚡ What does this code show?
    let name = "Meera";
    console.log("Hello, " + name + "!"); (a) Hello, name! (b) name (c) Hello, Meera! (d) Meera
30. 30.⚡ What number does this code print?
    let a = 12;
    let b = 8;
    console.log(a * b);
31. 31.⚡ What number does this code print?
    let score = 7;
    score = score + 5;
    score = score - 3;
    console.log(score);
32. 32.⚡ What does this code print? (Look at the quotes!)
    let x = "6";
    let y = 8;
    console.log(x + y); (a) 14 (b) 68 (c) Error
33. 33.⚡ What number does this code print?
    let a = 52;
    let b = 3;
    console.log(a + b);
34. 34.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Arjun! (c) Arjun (d) name
35. 35.⚡ Which JavaScript word runs code when true? (a) if (b) alert() (c) let (d) for
36. 36.⚡ What number does this code print?
    let a = 42;
    let b = 10;
    console.log(a + b);
37. 37.⚡ 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
38. 38.⚡ What number does this code print?
    let runs = 30;
    runs = runs + 4;
    runs = runs - 3;
    console.log(runs);
39. 39.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Welcome, Zoya! (d) Zoya
40. 40.⚡ What does this code show?
    let name = "Riya";
    alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Riya (d) Hi, Riya!

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