App Dev Worksheet: Functions

App development lesson 20: Functions · Set 318 · 40 questions

Developer's tip (Write once, use often): function name(parameter) { …; return result; } — call it with name(value). Work out each call separately, then finish the line. Inside a function, if / return can give different results for different inputs.

1. 1.🧰 What does return do in a function? (a) closes the screen (b) sends back a value (c) deletes the app (d) repeats the code
2. 2.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(15, 4));
3. 3.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(80, 2));
4. 4.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(35, 5));
5. 5.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(2) + points(3));
6. 6.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(55, 4));
7. 7.🧰 What does this code show?
   function greet(name) {
     return "Hello, " + name + "!";
   }
   show(greet("Riya")); (a) Hello, Riya! (b) Riya (c) greet (d) Hello, name!
8. 8.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(75, 5));
9. 9.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(14));
10. 10.🧰 Why write a function? (a) to make code longer (b) to reuse code (c) to slow the app (d) to hide errors
11. 11.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 30;
    }
    show(fee(4) + fee(2));
12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(4));
13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir")); (a) Kabir (b) Hello, Kabir! (c) greet (d) Hello, name!
14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 3));
15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 2));
17. 17.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) run greet (d) greet[]
18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 3));
19. 19.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(27));
20. 20.🧰 What is a function? (a) a screen size (b) a type of phone (c) a list of colours (d) a named block of code
21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 6));
22. 22.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(3));
23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(29));
24. 24.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(17));
25. 25.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(0));
26. 26.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
27. 27.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman")); (a) Aman (b) Hello, name! (c) greet (d) Hello, Aman!
28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 4));
29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Meera")); (a) Meera (b) greet (c) Hi, Meera! (d) Hi, name!
30. 30.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 30;
    }
    show(fee(8) + fee(2));
31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
32. 32.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(39));
33. 33.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 30;
    }
    show(fee(8) + fee(10));
34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 2));
35. 35.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(25));
36. 36.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 20;
    }
    show(fee(12) + fee(3));
37. 37.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 20;
    }
    show(fee(8) + fee(4));
38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(1));
39. 39.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 20;
    }
    show(fee(11) + fee(1));
40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(4));

Free app development lessons, practice and worksheets at talentjr.in/app-development-for-students