JavaScript Worksheet: Basics

HTML and CSS lesson 25: JavaScript basics · Set 43 · 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 table (d) a pop-up box
2. 2.⚡ What number does this code print?
   let marks = 13;
   marks = marks + 12;
   marks = marks - 5;
   console.log(marks);
3. 3.⚡ Which JavaScript word repeats code? (a) for (b) let (c) alert() (d) if
4. 4.⚡ What number does this code print?
   let a = 41;
   let b = 2;
   console.log(a + b);
5. 5.⚡ What number does this code print?
   let a = 25;
   let b = 19;
   console.log(a + b);
6. 6.⚡ Where does console.log() show its output? (a) on the title bar (b) on the printer (c) in the console (d) in the address bar
7. 7.⚡ Which word makes a new variable? (a) give (b) let (c) put (d) make
8. 8.⚡ What does this code show?
   let name = "Arjun";
   console.log("Hi, " + name + "!"); (a) Hi, name! (b) name (c) Arjun (d) Hi, Arjun!
9. 9.⚡ What number does this code print?
   let runs = 30;
   runs = runs + 6;
   runs = runs - 19;
   console.log(runs);
10. 10.⚡ What number does this code print?
    let a = 42;
    let b = 5;
    console.log(a - b);
11. 11.⚡ A JavaScript file usually ends with which extension? (a) .js (b) .jpg (c) .css (d) .html
12. 12.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 2;
    console.log(x + y); (a) Error (b) 82 (c) 10
13. 13.⚡ What number does this code print?
    let a = 40;
    let b = 13;
    console.log(a + b);
14. 14.⚡ What does this code show?
    let name = "Aman";
    alert("Hi, " + name + "!"); (a) name (b) Hi, name! (c) Hi, Aman! (d) Aman
15. 15.⚡ What number does this code print?
    let marks = 17;
    marks = marks + 20;
    marks = marks - 13;
    console.log(marks);
16. 16.⚡ Which tag holds JavaScript in a page? (a) <code> (b) <style> (c) <js> (d) <script>
17. 17.⚡ What number does this code print?
    let a = 3;
    let b = 9;
    console.log(a * b);
18. 18.⚡ Which JavaScript word writes in the console? (a) if (b) console.log() (c) let (d) alert()
19. 19.⚡ What does JavaScript add to a web page? (a) actions and changes (b) the domain name (c) only colours (d) the page title
20. 20.⚡ What number does this code print?
    let a = 18;
    let b = 20;
    console.log(a + b);
21. 21.⚡ What does this code print? (Look at the quotes!)
    let x = "8";
    let y = 4;
    console.log(x + y); (a) 12 (b) Error (c) 84
22. 22.⚡ What number does this code print?
    let a = 9;
    let b = 10;
    console.log(a * b);
23. 23.⚡ What number does this code print?
    let a = 29;
    let b = 8;
    console.log(a - b);
24. 24.⚡ What number does this code print?
    let a = 8;
    let b = 11;
    console.log(a * b);
25. 25.⚡ What number does this code print?
    let score = 23;
    score = score + 12;
    score = score - 6;
    console.log(score);
26. 26.⚡ What does this code show?
    let name = "Meera";
    alert("Well done, " + name + "!"); (a) Well done, Meera! (b) Well done, name! (c) Meera (d) name
27. 27.⚡ What number does this code print?
    let a = 55;
    let b = 38;
    console.log(a + b);
28. 28.⚡ What number does this code print?
    let a = 40;
    let b = 1;
    console.log(a - b);
29. 29.⚡ What number does this code print?
    let a = 7;
    let b = 1;
    console.log(a - b);
30. 30.⚡ Which JavaScript word makes a new variable? (a) if (b) alert() (c) for (d) let
31. 31.⚡ What number does this code print?
    let runs = 29;
    runs = runs + 7;
    runs = runs - 6;
    console.log(runs);
32. 32.⚡ What number does this code print?
    let a = 35;
    let b = 24;
    console.log(a - b);
33. 33.⚡ What number does this code print?
    let apples = 28;
    apples = apples + 20;
    apples = apples - 31;
    console.log(apples);
34. 34.⚡ What number does this code print?
    let a = 29;
    let b = 31;
    console.log(a + b);
35. 35.⚡ What number does this code print?
    let a = 58;
    let b = 13;
    console.log(a - b);
36. 36.⚡ What does this code show?
    let name = "Zoya";
    console.log("Welcome, " + name + "!"); (a) Welcome, name! (b) Zoya (c) name (d) Welcome, Zoya!
37. 37.⚡ Which JavaScript word shows a pop-up box? (a) alert() (b) if (c) let (d) for
38. 38.⚡ What number does this code print?
    let score = 14;
    score = score + 13;
    score = score - 18;
    console.log(score);
39. 39.⚡ What number does this code print?
    let a = 37;
    let b = 24;
    console.log(a - b);
40. 40.⚡ What does this code show?
    let name = "Aman";
    alert("Welcome, " + name + "!"); (a) Welcome, name! (b) Welcome, Aman! (c) Aman (d) name

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