App Dev Worksheet: Functions

App development lesson 20: Functions · Set 644 · 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 30;
   }
   show(fee(2) + fee(7));
2. 2.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code
3. 3.🧰 What does this code show?
   function greet(name) {
     return "Hi, " + name + "!";
   }
   show(greet("Aman")); (a) Hi, name! (b) Aman (c) Hi, Aman! (d) greet
4. 4.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(75, 3));
5. 5.🧰 How do you run (call) a function called greet? (a) run greet (b) #greet (c) greet() (d) greet[]
6. 6.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(22));
7. 7.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(3) + points(2));
8. 8.🧰 What does this code show?
   function greet(name) {
     return "Welcome, " + name + "!";
   }
   show(greet("Kabir")); (a) Welcome, Kabir! (b) Welcome, name! (c) Kabir (d) greet
9. 9.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(10, 5));
10. 10.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(19));
11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman")); (a) Hello, name! (b) Hello, Aman! (c) Aman (d) greet
12. 12.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 3));
13. 13.🧰 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(10) + fee(7));
14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 5));
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 30;
    }
    show(fee(9) + fee(6));
16. 16.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya")); (a) greet (b) Welcome, Zoya! (c) Zoya (d) Welcome, name!
17. 17.🧰 In function tip(bill), what is bill? (a) an event (b) a screen (c) a loop (d) a parameter
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 60;
    }
    show(fee(7) + fee(3));
19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(35));
20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 6));
21. 21.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya")); (a) Riya (b) Hi, name! (c) greet (d) Hi, Riya!
22. 22.🧰 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(8));
23. 23.🧰 What does return do in a function? (a) closes the screen (b) deletes the app (c) sends back a value (d) repeats the code
24. 24.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(31));
25. 25.🧰 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(11) + fee(12));
26. 26.🧰 Why write a function? (a) to hide errors (b) to make code longer (c) to reuse code (d) to slow the app
27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(30, 5));
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 20;
    }
    show(fee(2) + fee(8));
29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(85, 2));
30. 30.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(21));
31. 31.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(10));
32. 32.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(20));
33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 2));
34. 34.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(20));
35. 35.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(5));
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 30;
    }
    show(fee(9) + fee(10));
37. 37.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(7));
38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(40, 5));
39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 2));
40. 40.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(18));

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