App Dev Worksheet: Functions

App development lesson 20: Functions · Set 366 · 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 number does this code show?
   function triple(n) {
     return n * 3;
   }
   show(triple(7));
2. 2.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(1) + points(0));
3. 3.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(2) + points(5));
4. 4.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(2) + points(0));
5. 5.🧰 What number does this code show?
   function triple(n) {
     return n * 3;
   }
   show(triple(18));
6. 6.🧰 What does this code show?
   function greet(name) {
     return "Welcome, " + name + "!";
   }
   show(greet("Kabir")); (a) Welcome, name! (b) Welcome, Kabir! (c) greet (d) Kabir
7. 7.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(34));
8. 8.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(100, 3));
9. 9.🧰 What number does this code show?
   function triple(n) {
     return n * 3;
   }
   show(triple(17));
10. 10.🧰 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(10) + fee(1));
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 60;
    }
    show(fee(8) + fee(6));
12. 12.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman")); (a) Aman (b) Hello, Aman! (c) Hello, name! (d) greet
13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman")); (a) Aman (b) greet (c) Hi, Aman! (d) Hi, name!
14. 14.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Meera")); (a) Well done, name! (b) Well done, Meera! (c) Meera (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 60;
    }
    show(fee(7) + fee(5));
16. 16.🧰 Why write a function? (a) to reuse code (b) to make code longer (c) to hide errors (d) to slow the app
17. 17.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(6));
18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Zoya")); (a) greet (b) Hello, Zoya! (c) Hello, name! (d) Zoya
19. 19.🧰 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(9) + fee(2));
20. 20.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
21. 21.🧰 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(1) + fee(7));
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 30;
    }
    show(fee(11) + fee(4));
23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(24));
24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 2));
25. 25.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 3));
26. 26.🧰 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(8));
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(11) + fee(7));
28. 28.🧰 What does return do in a function? (a) sends back a value (b) closes the screen (c) repeats the code (d) deletes the app
29. 29.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir")); (a) Hello, Kabir! (b) Kabir (c) Hello, name! (d) greet
30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
31. 31.🧰 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(5) + fee(3));
32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Kabir")); (a) greet (b) Hi, name! (c) Kabir (d) Hi, Kabir!
33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 4));
34. 34.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya")); (a) Welcome, Zoya! (b) greet (c) Zoya (d) Welcome, name!
35. 35.🧰 In function tip(bill), what is bill? (a) an event (b) a loop (c) a parameter (d) a screen
36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));
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(7));
38. 38.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun")); (a) Arjun (b) Well done, name! (c) greet (d) Well done, Arjun!
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 30;
    }
    show(fee(3) + fee(2));
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 40;
    }
    show(fee(4) + fee(5));

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