App Dev Worksheet: Functions

App development lesson 20: Functions · Set 601 · 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(10, 3));
2. 2.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(95, 2));
3. 3.🧰 What does this code show?
   function greet(name) {
     return "Welcome, " + name + "!";
   }
   show(greet("Kabir")); (a) greet (b) Welcome, name! (c) Kabir (d) Welcome, Kabir!
4. 4.🧰 Why write a function? (a) to make code longer (b) to reuse code (c) to hide errors (d) to slow the app
5. 5.🧰 In function tip(bill), what is bill? (a) a parameter (b) a loop (c) a screen (d) an event
6. 6.🧰 What number does this code show?
   function triple(n) {
     return n * 3;
   }
   show(triple(29));
7. 7.🧰 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(3) + fee(3));
8. 8.🧰 What does this code show?
   function greet(name) {
     return "Welcome, " + name + "!";
   }
   show(greet("Aman")); (a) Aman (b) greet (c) Welcome, name! (d) Welcome, Aman!
9. 9.🧰 What number does this code show?
   function total(price, qty) {
     return price * qty;
   }
   show(total(35, 2));
10. 10.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Arjun")); (a) greet (b) Hello, Arjun! (c) Arjun (d) Hello, name!
11. 11.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Kabir")); (a) greet (b) Well done, name! (c) Kabir (d) Well done, Kabir!
12. 12.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(32));
13. 13.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Riya")); (a) greet (b) Riya (c) Hello, name! (d) Hello, Riya!
14. 14.🧰 How do you run (call) a function called greet? (a) #greet (b) greet() (c) greet[] (d) run greet
15. 15.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(45, 2));
16. 16.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 4));
17. 17.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(60, 4));
18. 18.🧰 What does this code show?
    function greet(name) {
      return "Hello, " + name + "!";
    }
    show(greet("Aman")); (a) greet (b) Hello, name! (c) Hello, Aman! (d) Aman
19. 19.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(34));
20. 20.🧰 What number does this code show?
    function triple(n) {
      return n * 3;
    }
    show(triple(8));
21. 21.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(20));
22. 22.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(37));
23. 23.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(75, 2));
24. 24.🧰 What does return do in a function? (a) closes the screen (b) repeats the code (c) deletes the app (d) sends back a value
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(12) + fee(12));
26. 26.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 2));
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(2) + fee(2));
28. 28.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(65, 3));
29. 29.🧰 What does this code show?
    function greet(name) {
      return "Well done, " + name + "!";
    }
    show(greet("Zoya")); (a) Zoya (b) greet (c) Well done, Zoya! (d) Well done, name!
30. 30.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(20, 3));
31. 31.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(80, 4));
32. 32.🧰 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(1) + fee(1));
33. 33.🧰 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(1));
34. 34.🧰 What number does this code show?
    function double(n) {
      return n * 2;
    }
    show(double(3));
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 40;
    }
    show(fee(3) + fee(3));
36. 36.🧰 What is a function? (a) a named block of code (b) a type of phone (c) a list of colours (d) a screen size
37. 37.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(5) + points(5));
38. 38.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(35, 3));
39. 39.🧰 What number does this code show?
    function points(stars) {
      return stars * 10 + 5;
    }
    show(points(1) + points(5));
40. 40.🧰 What number does this code show?
    function total(price, qty) {
      return price * qty;
    }
    show(total(50, 4));

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