JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 61 · 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 number does this code print?
   let runs = 7;
   runs = runs + 6;
   runs = runs - 12;
   console.log(runs);
2. 2.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .html (c) .css (d) .jpg
3. 3.⚡ What does this code print? (Look at the quotes!)
   let x = "1";
   let y = 7;
   console.log(x + y); (a) Error (b) 8 (c) 17
4. 4.⚡ Which JavaScript word repeats code? (a) let (b) alert() (c) console.log() (d) for
5. 5.⚡ What does this code show?
   let name = "Aman";
   alert("Welcome, " + name + "!"); (a) Aman (b) name (c) Welcome, name! (d) Welcome, Aman!
6. 6.⚡ Which JavaScript word makes a new variable? (a) alert() (b) let (c) console.log() (d) if
7. 7.⚡ What number does this code print?
   let marks = 27;
   marks = marks + 4;
   marks = marks - 19;
   console.log(marks);
8. 8.⚡ What does this code print? (Look at the quotes!)
   let x = "7";
   let y = 2;
   console.log(x + y); (a) 72 (b) 9 (c) Error
9. 9.⚡ What does this code show?
   let name = "Aman";
   alert("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Aman (d) Hi, Aman!
10. 10.⚡ What does JavaScript add to a web page? (a) only colours (b) actions and changes (c) the domain name (d) the page title
11. 11.⚡ What does alert() show? (a) a pop-up box (b) a new tab (c) a table (d) a picture
12. 12.⚡ What number does this code print?
    let apples = 11;
    apples = apples + 15;
    apples = apples - 20;
    console.log(apples);
13. 13.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 1;
    console.log(x + y); (a) Error (b) 41 (c) 5
14. 14.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 6;
    console.log(x + y); (a) Error (b) 26 (c) 8
15. 15.⚡ What does this code show?
    let name = "Aman";
    alert("Hello, " + name + "!"); (a) Hello, name! (b) Hello, Aman! (c) name (d) Aman
16. 16.⚡ What number does this code print?
    let runs = 18;
    runs = runs + 5;
    runs = runs - 11;
    console.log(runs);
17. 17.⚡ What number does this code print?
    let runs = 6;
    runs = runs + 6;
    runs = runs - 7;
    console.log(runs);
18. 18.⚡ What does this code print? (Look at the quotes!)
    let x = "2";
    let y = 2;
    console.log(x + y); (a) 4 (b) Error (c) 22
19. 19.⚡ Which JavaScript word shows a pop-up box? (a) for (b) let (c) console.log() (d) alert()
20. 20.⚡ Which tag holds JavaScript in a page? (a) <style> (b) <code> (c) <script> (d) <js>
21. 21.⚡ What number does this code print?
    let a = 3;
    let b = 3;
    console.log(a * b);
22. 22.⚡ What number does this code print?
    let runs = 25;
    runs = runs + 14;
    runs = runs - 10;
    console.log(runs);
23. 23.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 9;
    console.log(x + y); (a) 10 (b) 19 (c) Error
24. 24.⚡ Which JavaScript word runs code when true? (a) for (b) console.log() (c) if (d) alert()
25. 25.⚡ What number does this code print?
    let a = 4;
    let b = 6;
    console.log(a * b);
26. 26.⚡ Which word makes a new variable? (a) give (b) let (c) make (d) put
27. 27.⚡ What number does this code print?
    let marks = 19;
    marks = marks + 13;
    marks = marks - 9;
    console.log(marks);
28. 28.⚡ What number does this code print?
    let a = 21;
    let b = 5;
    console.log(a - b);
29. 29.⚡ Which JavaScript word writes in the console? (a) let (b) alert() (c) if (d) console.log()
30. 30.⚡ What number does this code print?
    let a = 43;
    let b = 3;
    console.log(a - b);
31. 31.⚡ What does this code print? (Look at the quotes!)
    let x = "9";
    let y = 8;
    console.log(x + y); (a) Error (b) 98 (c) 17
32. 32.⚡ What does this code show?
    let name = "Kabir";
    console.log("Welcome, " + name + "!"); (a) name (b) Welcome, name! (c) Kabir (d) Welcome, Kabir!
33. 33.⚡ Where does console.log() show its output? (a) on the printer (b) on the title bar (c) in the address bar (d) in the console
34. 34.⚡ What does this code show?
    let name = "Arjun";
    alert("Hello, " + name + "!"); (a) Hello, Arjun! (b) name (c) Arjun (d) Hello, name!
35. 35.⚡ What does this code show?
    let name = "Aman";
    console.log("Welcome, " + name + "!"); (a) Aman (b) Welcome, Aman! (c) name (d) Welcome, name!
36. 36.⚡ What does this code print? (Look at the quotes!)
    let x = "4";
    let y = 9;
    console.log(x + y); (a) Error (b) 49 (c) 13
37. 37.⚡ What does this code print? (Look at the quotes!)
    let x = "1";
    let y = 5;
    console.log(x + y); (a) 15 (b) 6 (c) Error
38. 38.⚡ What number does this code print?
    let a = 52;
    let b = 18;
    console.log(a + b);
39. 39.⚡ What does this code show?
    let name = "Kabir";
    alert("Welcome, " + name + "!"); (a) Welcome, Kabir! (b) Kabir (c) name (d) Welcome, name!
40. 40.⚡ What number does this code print?
    let a = 3;
    let b = 8;
    console.log(a * b);

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