App Dev Worksheet: Functions

App development lesson 20: Functions · Set 603 · 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.🧰 A museum app works out the entry fee. What number does this code show?
   function fee(age) {
     if (age < 5) {
       return 0;
     }
     return 50;
   }
   show(fee(6) + fee(1));
2. 2.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(31));
3. 3.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(75, 5));
4. 4.🧰 A museum app works out the entry fee. What number does this code show?
   function fee(age) {
     if (age < 5) {
       return 0;
     }
     return 40;
   }
   show(fee(11) + fee(2));
5. 5.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(10, 3));
6. 6.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(70, 3));
7. 7.🧰 A museum app works out the entry fee. What number does this code show?
   function fee(age) {
     if (age < 5) {
       return 0;
     }
     return 60;
   }
   show(fee(11) + fee(9));
8. 8.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(4) + points(5));
9. 9.🧰 What is a function? (a) a screen size (b) a named block of code (c) a type of phone (d) a list of colours
10. 10.🧰 What does return do in a function? (a) deletes the app (b) sends back a value (c) repeats the code (d) closes the screen
11. 11.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Riya")); (a) Well done, name! (b) Riya (c) greet (d) Well done, Riya!
12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(30));
13. 13.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) an event (d) a screen
14. 14.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) run greet (d) #greet
15. 15.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 50;
    }
    show(fee(8) + fee(6));
16. 16.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
17. 17.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(27));
18. 18.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 50;
    }
    show(fee(12) + fee(9));
19. 19.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Aman")); (a) greet (b) Welcome, Aman! (c) Aman (d) Welcome, name!
20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(29));
21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 5));
22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));
23. 23.🧰 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(5) + fee(4));
24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 2));
25. 25.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(16));
26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 3));
27. 27.🧰 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(4) + fee(7));
28. 28.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 40;
    }
    show(fee(6) + fee(9));
29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 3));
30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 5));
31. 31.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya")); (a) Hello, name! (b) Hello, Zoya! (c) greet (d) Zoya
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(9) + fee(4));
34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 6));
35. 35.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 3));
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(2) + fee(12));
37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(5));
38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 3));
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 50;
    }
    show(fee(8) + fee(5));
40. 40.🧰 A museum app works out the entry fee. What number does this code show?
    function fee(age) {
      if (age < 5) {
        return 0;
      }
      return 50;
    }
    show(fee(9) + fee(9));

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