Three ways to find minimum and maximum values in a Java array of primitive types.

In Java you can find maximum or minimum value in a numeric array by looping through the array. Here is the code to do that.

public static int getMaxValue(int[] numbers){
  int maxValue = numbers[0];
  for(int i=1;i < numbers.length;i++){
    if(numbers[i] > maxValue){
	  maxValue = numbers[i];
	}
  }
  return maxValue;
}

public static int getMinValue(int[] numbers){
  int minValue = numbers[0];
  for(int i=1;i<numbers.length;i++){
    if(numbers[i] < minValue){
	  minValue = numbers[i];
	}
  }
  return minValue;
}

These are very straightforward methods to get the maximum or minimum value of an array but there is a cleaner way to do this.

Using Arrays.sort method to Find Maximum and Minimum Values in an Array

 

int[] nums={6,-1,-2,-3,0,1,2,3,4};
Arrays.sort(nums);
System.out.println("Minimum = " + nums[0]);
System.out.println("Maximum = " + nums[nums.length-1]);

You cannot make it simpler than this. You will need to import java.util.* to use Arrays class.

Using Recursion to Find Maximum and Minimum Values in an Array

Yet another way to get these values is using recursion.

Following methods show how to use recursion to find maximum and minimum values of an array.

public static int getMaximumValueUsingRecursion(int[] numbers, int a, int n){
  return a>=numbers.length?n:Math.max(n,max(numbers,a+1,numbers[a]>n?numbers[a]:n));
  }
 private static int getMinimumValueUsingRecursion(int[] numbers, int a, int n) {
     return a==numbers.length?n:Math.min(n,min(numbers,a+1,numbers[a]<n?numbers[a]:n));
 }

 

Here is an executable Java class demonstrating the use of all three methods.

  import java.util.Arrays;
  public class MinMaxValues{

	public static void main (String args[]){
	   int numbers[]= {1,5,-9,12,-3,89, 18,23,4,-6};
	   //Find minimum (lowest) value in array using loop
	   System.out.println("Minimum Value = " + getMinValue(numbers));
	   //Find maximum (largest) value in array using loop
	   System.out.println("Maximum Value = " + getMaxValue(numbers));

	    //Find minimum (lowest) value in array by sorting array
	   System.out.println("Minimum Value = " + minValue(numbers));
	   //Find maximum (largest) value in array by sorting array
	   System.out.println("Maximum Value = " + maxValue(numbers));

	   //Find minimum (lowest) value in array using recursion
	   System.out.println("Minimum Value = " + getMinimumValueUsingRecursion(numbers,0,numbers[0]));

	   //Find maximum (largest) value in array using recursion
	   System.out.println("Maximum Value = " + getMaximumValueUsingRecursion(numbers,0,numbers[0]));

	}

	//Find maximum (largest) value in array using loop
	public static int getMaxValue(int[] numbers){
		int maxValue = numbers[0];
		for(int i=1;i<numbers.length;i++){
			if(numbers[i] > maxValue){
				maxValue = numbers[i];
			}
		}
		return maxValue;
	}

	//Find minimum (lowest) value in array using loop
	public static int getMinValue(int[] numbers){
		int minValue = numbers[0];
		for(int i=1;i<numbers.length;i++){
			if(numbers[i] < minValue){
				minValue = numbers[i];
			}
		}
		return minValue;
	}

	//Find minimum (lowest) value in array using array sort
	public static int minValue(int[] numbers){
	  Arrays.sort(numbers);
	  return numbers[0];
	}

	//Find maximum (largest) value in array using array sort
	public static int maxValue(int[] numbers){
	  Arrays.sort(numbers);
	  return numbers[numbers.length-1];
	}

	//Find maximum (largest) value in array using recursion
	public static int getMaximumValueUsingRecursion(int[] numbers, int a, int n){
		return a>=numbers.length?n:Math.max(n,getMax(numbers,a+1,numbers[a]>n?numbers[a]:n));
	}

	//Find minimum (lowest) value in array using recursion
	private static int getMinimumValueUsingRecursion(int[] numbers, int a, int n) {
     return a==numbers.length?n:Math.min(n,getMin(numbers,a+1,numbers[a]<n?numbers[a]:n));
    }

}

So which method do you like the most?