App Dev Worksheet: Functions

App development lesson 20: Functions · Set 779 · 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(50, 4));
2. 2.🧰 What does this code show?
   function greet(name) {
     return "Hi, " + name + "!";
   }
   show(greet("Zoya")); (a) Hi, name! (b) Hi, Zoya! (c) greet (d) Zoya
3. 3.🧰 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(4) + fee(10));
4. 4.🧰 What number does this code show?
   function double(n) {
     return n * 2;
   }
   show(double(16));
5. 5.🧰 What is a function? (a) a screen size (b) a list of colours (c) a named block of code (d) a type of phone
6. 6.🧰 What does return do in a function? (a) deletes the app (b) sends back a value (c) repeats the code (d) closes the screen
7. 7.🧰 What does this code show?
   function greet(name) {
     return "Welcome, " + name + "!";
   }
   show(greet("Zoya")); (a) Welcome, name! (b) Welcome, Zoya! (c) Zoya (d) greet
8. 8.🧰 What number does this code show?
   function points(stars) {
     return stars * 10 + 5;
   }
   show(points(2) + points(5));
9. 9.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(15, 4));
10. 10.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(95, 5));
11. 11.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun")); (a) Arjun (b) greet (c) Hello, Arjun! (d) Hello, name!
12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(35));
13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Meera")); (a) Hello, name! (b) greet (c) Meera (d) Hello, Meera!
14. 14.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 5));
15. 15.🧰 Why write a function? (a) to slow the app (b) to hide errors (c) to reuse code (d) to make code longer
16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 4));
17. 17.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(6));
18. 18.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(4) + points(1));
19. 19.🧰 What does this code show?
    function greet(name) {
      return "Hi, " + name + "!";
    }
    show(greet("Riya")); (a) Riya (b) Hi, Riya! (c) Hi, name! (d) greet
20. 20.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(90, 6));
21. 21.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(25, 2));
22. 22.🧰 How do you run (call) a function called greet? (a) greet() (b) greet[] (c) run greet (d) #greet
23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(100, 2));
24. 24.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(21));
25. 25.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(11));
26. 26.🧰 What does this code show?
    function greet(name) {
      return "Welcome, " + name + "!";
    }
    show(greet("Meera")); (a) Meera (b) Welcome, Meera! (c) Welcome, name! (d) greet
27. 27.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(10, 6));
28. 28.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(5));
29. 29.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 4));
30. 30.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(38));
31. 31.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(0));
32. 32.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(2));
33. 33.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(34));
34. 34.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Arjun")); (a) Well done, Arjun! (b) greet (c) Arjun (d) Well done, name!
35. 35.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(3) + points(4));
36. 36.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 3));
37. 37.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(27));
38. 38.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(2) + points(1));
39. 39.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Kabir")); (a) greet (b) Hello, Kabir! (c) Hello, name! (d) Kabir
40. 40.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(33));

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