App Dev Worksheet: Functions

App development lesson 20: Functions · Set 117 · 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(25, 6));
2. 2.🧰 How do you run (call) a function called greet? (a) greet[] (b) #greet (c) greet() (d) run greet
3. 3.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(32));
4. 4.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(65, 3));
5. 5.🧰 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(3));
6. 6.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(75, 4));
7. 7.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(35, 5));
8. 8.🧰 Why write a function? (a) to hide errors (b) to slow the app (c) to reuse code (d) to make code longer
9. 9.🧰 What number does this code show?
   function triple(n) {
     return n * 3;
   }
   show(triple(11));
10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 5));
11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya")); (a) Hi, name! (b) Riya (c) greet (d) Hi, Riya!
12. 12.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(0));
13. 13.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(14));
14. 14.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(27));
15. 15.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Zoya")); (a) Welcome, Zoya! (b) Zoya (c) greet (d) Welcome, name!
16. 16.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(9));
17. 17.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(2));
18. 18.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 5));
19. 19.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) sends back a value (d) deletes the app
20. 20.🧰 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(8));
21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
22. 22.🧰 In function tip(bill), what is bill? (a) a parameter (b) a screen (c) a loop (d) an event
23. 23.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(24));
24. 24.🧰 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(8) + fee(11));
25. 25.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Zoya")); (a) Hi, Zoya! (b) Zoya (c) Hi, name! (d) greet
26. 26.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(23));
27. 27.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(2));
28. 28.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(13));
29. 29.🧰 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(2));
30. 30.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
31. 31.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Kabir")); (a) greet (b) Welcome, Kabir! (c) Kabir (d) Welcome, name!
32. 32.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman")); (a) Hello, Aman! (b) Aman (c) Hello, name! (d) greet
33. 33.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 4));
34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(27));
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 20;
    }
    show(fee(11) + fee(8));
36. 36.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(16));
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 40;
    }
    show(fee(12) + fee(11));
38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 5));
39. 39.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 5));
40. 40.🧰 What is a function? (a) a type of phone (b) a list of colours (c) a screen size (d) a named block of code

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