Question

In Java, Assume we have these two methods. public static boolean allAreEqual(int n1, int n2, int n3) { return n1 == n2 && n2 == n3; } public static boolean mystery(int n1, int n2, int n3) { return !allAreEqual(n1, n2, n3) && (n1 == n2 || n1 == n3 || n2 == n3); } Part 1: What value will be returned by the following method calls? mystery(5, 5, 5) mystery(5, 5, 1) Part 2: What does the mystery method do in general? What would be a good name for this method?

Answer 1

Part 1: method call mystery(5, 5, 5)

Answer :false

Explanation :

• method allAreEqual(5,5,5) will return true because 5==5 && 5==5 will return true && true which returns true
• (n1 == n2 || n1 == n3 || n2 == n3) will return true || true is true ==> true || true ==> will be true
• hence return !allAreEqual(n1, n2, n3) && (n1 == n2 || n1 == n3 || n2 == n3);
• !true && true ==> false && true ==> false

Below screen shows the output

л во 6 7 Main.java 1 //Main() method 2 public class Main 3 - 4. public static void main(String[] args) { System.out.println(mystery(5, 5, 5)); } 8 public static boolean allAreEqual(int n1, int n2, int n3) 9 { 10 return n1 n2 && n2 == n3; 11 12 } 13 public static boolean mystery(int ni, int n2, int n3) 14 { 15 return !allAreEqual(n1, n2, n3) && (n1 == n2 || n1 == n3 || n2 == n3); 16 17 } 18 } 19 ir À w N 9 input false

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Part 1: method call mystery(5, 5, 1)

Answer :false

Explanation :

• method allAreEqual(5,5,1) will return false because 5==5 && 5==1 will return true && false which returns false
• (n1 == n2 || n1 == n3 || n2 == n3) will return true || false is true ==> true || false ==> will be true
• hence return !allAreEqual(n1, n2, n3) && (n1 == n2 || n1 == n3 || n2 == n3); will be
• !false && true ==> true && true ==> true

Below screen shows the output

000 Main.java 1 //Main() method 2 public class Main 3- { 4 public static void main(String[] args) { 5 System.out.println(mystery(5, 5, 1)); 7 } public static boolean allAreEqual(int n, int n2, int n3) 9 { 10 return n1 n2 && n2 n3; 11 12 } 13 public static boolean mystery(int ni, int n2, int n3) 14 { 15 return !allAreEqual(n1, n2, n3) && (n1 n2 || n1 == n3 || n2 16 17 } 18 } a n3); input true

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mystery method do in general :

• This method will all the method allAreEqual() and will compre the each parameter value and will return the result.

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good name for this method :

• These methods compare parameters hence will be called as compareParameters()