Java Program to Find the Largest of three Numbers

Last Updated : 02 Jul, 2024

Problem Statement: Given three numbers x, y, and z of which aim is to get the largest among these three numbers.

Example:

Input: x = 7, y = 20, z = 56
Output: 56 // value stored in variable z

Flowchart For Largest of 3 numbers:

Algorithm to find the largest of three numbers:

1. Start
2. Read the three numbers to be compared, as A, B and C
3. Check if A is greater than B.

 3.1 If true, then check if A is greater than C
 If true, print 'A' as the greatest number
 If false, print 'C' as the greatest number

 3.2 If false, then check if B is greater than C
 If true, print 'B' as the greatest number
 If false, print 'C' as the greatest number
4. End

Approaches:

Using Ternary operator
Using if-else

Approach 1: Using Ternary operator

The syntax for the conditional operator:

ans = (conditional expression) ? execute if true : execute if false

If the condition is true then execute the statement before the colon
If the condition is false then execute a statement after colon so

largest = z > (x>y ? x:y) ? z:((x>y) ? x:y);

Illustration:

x = 5, y= 10, z = 3

largest = 3>(5>10 ? 5:10) ? 3: ((5>10) ? 5:10);
largest = 3>10 ? 3 : 10
largest = 10

Java

// Java Program to Find the Biggest of 3 Numbers // Importing generic Classes/Files import java.io.*; class GFG {    // Function to find the biggest of three numbers  static int biggestOfThree(int x, int y, int z)  {  return z > (x > y ? x : y) ? z : ((x > y) ? x : y);  }  // Main driver function  public static void main(String[] args)  {  // Declaring variables for 3 numbers  int a, b, c;  // Variable holding the largest number  int largest;  a = 5;  b = 10;  c = 3;  // Calling the above function in main  largest = biggestOfThree(a, b, c);  // Printing the largest number  System.out.println(largest  + " is the largest number.");  } }

Output

10 is the largest number.

Approach 2: Using the if-else statements

In this method, if-else statements will compare and check for the largest number by comparing numbers. 'If' will check whether 'x' is greater than 'y' and 'z' or not. 'else if' will check whether 'y' is greater than 'x' and 'z' or not. And if both the conditions are false then 'z' will be the largest number.

Java

// Java Program to Find the Biggest of 3 Numbers // Importing generic Classes/Files import java.io.*; class GFG {  // Function to find the biggest of three numbers  static int biggestOfThree(int x, int y, int z)  {  // Comparing all 3 numbers  if (x >= y && x >= z)  // Returning 1st number if largest  return x;  // Comparing 2nd no with 1st and 3rd no  else if (y >= x && y >= z)  // Return z if the above conditions are false  return y;  else  // Returning 3rd no, Its sure it is greatest  return z;  }  // Main driver function  public static void main(String[] args)  {  int a, b, c, largest;  // Considering random integers three numbers  a = 5;  b = 10;  c = 3;  // Calling the function in main() body  largest = biggestOfThree(a, b, c);  // Printing the largest number  System.out.println(largest  + " is the largest number.");  } }

Output

10 is the largest number.

Approach 3 : Using Collections.max() method and ArrayList

Java

// Java Program to Find the Largest of three Numbers // Using Collections.max() method import java.lang.*; import java.util.*; class GFG {  public static void main(String[] args)  {  int a, b, c;  // Considering random integers three numbers  a = 5;  b = 10;  c = 3;  ArrayList<Integer> x = new ArrayList<>();  x.add(a);  x.add(b);  x.add(c);  // Printing the largest number  System.out.println(Collections.max(x)  + " is the largest number.");  } }

Output

10 is the largest number.

Time Complexity: O(n)
Auxiliary Space: O(n), where n is length of ArrayList.

Approach 4: Using Math.max() method

This approach utilizes the Math.max() method from the java.lang.Math class. It takes two numbers as arguments and returns the larger of the two. This method is chained to find the largest between the larger of num1 and num2 and num3.

Java

public class LargestNumber {  public static void main(String[] args) {  int num1 = 10, num2 = 20, num3 = 15;  int largest = Math.max(Math.max(num1, num2), num3);  System.out.println("The largest number is: " + largest);  } }