App Dev Worksheet: Functions

App development lesson 20: Functions · Set 233 · 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 total(price, qty) {
     return price * qty;
   }
   show(total(20, 3));
2. 2.🧰 What does return do in a function? (a) deletes the app (b) sends back a value (c) closes the screen (d) repeats the code
3. 3.🧰 What does this code show?
   function greet(name) {
     return "Well done, " + name + "!";
   }
   show(greet("Arjun")); (a) Arjun (b) Well done, Arjun! (c) Well done, name! (d) greet
4. 4.🧰 What does this code show?
   function greet(name) {
     return "Welcome, " + name + "!";
   }
   show(greet("Arjun")); (a) Welcome, Arjun! (b) Arjun (c) Welcome, name! (d) greet
5. 5.🧰 How do you run (call) a function called greet? (a) run greet (b) greet[] (c) greet() (d) #greet
6. 6.🧰 What does this code show?
   function greet(name) {
     return "Hi, " + name + "!";
   }
   show(greet("Kabir")); (a) Kabir (b) greet (c) Hi, Kabir! (d) Hi, name!
7. 7.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(13));
8. 8.🧰 In function tip(bill), what is bill? (a) an event (b) a parameter (c) a loop (d) a screen
9. 9.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(12));
10. 10.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(11));
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 50;
    }
    show(fee(7) + fee(9));
12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Arjun")); (a) greet (b) Arjun (c) Hi, Arjun! (d) Hi, name!
14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 2));
15. 15.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
16. 16.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(1));
17. 17.🧰 What is a function? (a) a list of colours (b) a screen size (c) a named block of code (d) a type of phone
18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 5));
19. 19.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(0));
20. 20.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
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 60;
    }
    show(fee(2) + fee(7));
22. 22.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(55, 6));
23. 23.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(35));
24. 24.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 5));
25. 25.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(4));
26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
27. 27.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(18));
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 30;
    }
    show(fee(4) + fee(5));
29. 29.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 2));
31. 31.🧰 Why write a function? (a) to slow the app (b) to reuse code (c) to hide errors (d) to make code longer
32. 32.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir")); (a) Welcome, Kabir! (b) Welcome, name! (c) Kabir (d) greet
33. 33.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Aman")); (a) Aman (b) Hi, Aman! (c) greet (d) Hi, name!
34. 34.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 6));
35. 35.🧰 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(1));
36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(70, 2));
37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(3));
38. 38.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman")); (a) greet (b) Hello, Aman! (c) Aman (d) Hello, name!
39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 3));
40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(8));

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