Java program to find second largest number in an array

Step 1:

    Iterate the given array

Step 2 (first if condition arr[i] > largest):

    If current array value is greater than largest value then

        Move the largest value to secondLargest and make

        current value as largest

Step 3 (second if condition arr[i] > secondLargest )  

  If the current value is smaller than largest and greater than secondLargest  then

        the current value becomes secondLargest

Program

package com.candidjava;

public class SecondLargest {

	public static void main(String[] args) {

		int arr[] = { 14, 46, 47, 86, 92, 52, 48, 36, 66, 85 };
		int largest = arr[0];
		int secondLargest = arr[0];
		
		System.out.println("The given array is:" );
		for (int i = 0; i < arr.length; i++) {
			System.out.print(arr[i]+"\t");
		}
		for (int i = 0; i < arr.length; i++) {

			if (arr[i] > largest) {
				secondLargest = largest;
				largest = arr[i];

			} else if (arr[i] > secondLargest) {
				secondLargest = arr[i];

			}
		}

		System.out.println("\nSecond largest number is:" + secondLargest);

	}
}

Output

The given array is:

14 46 47 86 92 52 48 36 66 85

Second largest number is:86

Comments

Suresh Sala
         It s wrong.. {5,4,3,2,1} it is showing output 5
Mohammad Javed
         The Above solution will not work if the Largest element is at array[0]. So, we should initialize the secondLargest and largest to zero. (The best approach will be to find the minimum in the array and then initialize it with min )
vishal
         Agree with Suresh and Javed
Ali Umar
         It is working fine. Thanks
PRADEEP KUMAR PALAI
         I completely agree with javed :) public static int secondLargestElement(int arr[]) { int lengtharr = arr.length; int secondlargest = 0; int lagest = 0; //displaying the array System.out.println("the given array is "); for (int i = 0; i < lengtharr; i++) { System.out.print(arr[i] + "\t"); } for (int i = 0; i < lengtharr; i++) { if(arr[i]>lagest) { secondlargest=lagest; lagest=arr[i]; }else if(arr[i]>secondlargest) { secondlargest=arr[i]; } } return secondlargest; }
Premji
         Pradeep have given good solution. It will work forever.
Badal
         Pradeep this code will fail when int arr[]= {-5, -7, -9} values will be passed to the secondLargestElement();
shaan rizvi
         class secondLargest { public static void main(String args[]) { int[] second=new int[7]; int[] arr={15,34,12,45,67,98,67,2}; int largest=arr[0]; int j=0; for(int i=1;ilargest) { largest=arr[i]; } else { second[j]=arr[i]; j++; } } System.out.println("first largest is "+largest); int secondL=second[0]; for(int k=1;k susanta send
         public static void main(String[] args) { //int numList[] = { 21, 12, 31, 13, 41, 14 }; //int numList[] = { 112,234,34324,191,408,131,507,809 , 0}; int numList[] = { 5,4,3,2,1,0}; int maxElement = 0; int secondHighestElement = 0; for (int arrElments : numList) { if (arrElments > maxElement) { secondHighestElement = maxElement; maxElement = arrElments; }else if(secondHighestElement < arrElments){ secondHighestElement = arrElments; } } System.out.println("maxElement ::" + maxElement); System.out.println("2ndMaxElement ::" + secondHighestElement);
susanta send
         This Logic is for sorting arrary in ascending order :- I am requesting you people to go through it and let me know if you have any concern .:::: Here is the Code :- ---------------------- public static void sortArrayElement() { // Sorting IntegerArray int numList[] = { 21, 12, -31, 13, 41, -14 }; int maxElement = 0; int interchangeElement = 0; for (int i = 0; i < numList.length; ++i) { for (int j = i + 1; j <= numList.length-1; ++j) { if (numList[i] > numList[j]) { interchangeElement = numList[i]; numList[i] = numList[j]; numList[j] = interchangeElement; } } } System.out.println("sortedArray :: "); //System.out.println("2ndMaxElement ::" +numList[numList.length-2]); for(int arraryElement:numList){ System.out.println(arraryElement); } }
Aditya
         I have the below solution working at O(n)... No need to sort the array int[] input = {5,4,3,2,1}; int firstLargest = 0; int secondLargest = 0; for(int i: input){ if(i>firstLargest){ secondLargest = firstLargest; firstLargest = i; } else if(i>secondLargest){ secondLargest = i; } } System.out.println(firstLargest + "-" + secondLargest);
Naveen
         In this program largest number is showing correctly, vut secind largest is always showing first element of array.. Please suggest other logic
coder
         package secondlargest; public class secondlargest { public static void main(String[] args) { // TODO Auto-generated method stub int [] array = {15,6,1,8,9,7,4,3}; int largest; int secondlargest; if(array[0]>array[1]) { largest = array[0]; secondlargest = array[1]; } else { largest = array[1]; secondlargest = array[0]; } for(int i=2;ilargest) { secondlargest = largest; largest = array[i]; } else if((array[i]secondlargest)) { secondlargest=array[i]; } } System.out.println("second largest is = " + secondlargest); } }
Siva
         public static void Second_Max_number(){ int i =0; int a[] = {2,6,7,5,4,3}; Arrays.sort(a); int M = 0; for(i=0; iM){ M= a[i]; } } System.out.println(a[i]); System.out.println("Second Max Number"+ M); }
Shekhar
         public class SecondHighestNumber { public static void main(String a[]){ int num[] = {45,35,78,2,35,1,78,25}; SecondHighestNumber tmn = new SecondHighestNumber(); tmn.printSecondHighestNumber(num); } public void printSecondHighestNumber(int[] numbers) { int max1 = Integer.MIN_VALUE; int max2 = Integer.MIN_VALUE; for (int number : numbers) { if (number > max1) { max2 = max1; max1 = number; } else if (number > max2 && number!=max1) { max2 = number; } } System.out.println("second highest number="+max2); } }
ram
         if you are taking first element large in complete series like int arr[] = { 98, 46, 47, 86, 92, 52, 48, 36, 66, 85 } then it always return first element [like here 98 ].that is wrong .
Rajkumar Singh
         import java.util.Arrays; public class SecondLargest { public static void main(String[] args) { int[] arr = { 14, 46, 47, 86, 92, 52, 48, 36, 66, 85 }; Arrays.sort(arr); int count=0; for (int i = arr.length-1; i >=0; i--) { if(count==1){ System.out.println(arr[i]); break; }else{ count++; } } } }
Rahul Chauhan
         public void findMax(int a[]){ int large = a[0]; int secondLast = a[0]; for(int i = 1 ; i < a.length ; i++){ if(large < a[i]){ secondLast = large; large = a[i]; } else if(a[i] > secondLast){ secondLast = a[i]; } else if(large == secondLast){ secondLast = a[i]; } } System.out.println("Large number "+large+" Second Last number "+secondLast); }
Rohin
         How will the program work if all the numbers entered in the array are equal
Vivekanand Chaturvedi
         int [] arr= {200,3,7,98,45,99,100,2,33,58,1,90,6,101}; Even when largest and 2nd largeset initialized with 0. Output is: largest: 200 2nd largest;0;
Dheeraj
         import java.lang.Math; // headers MUST be above the first class // one class needs to have a main() method public class HelloWorld { // arguments are passed using the text field below this editor public static void main(String[] args) { int[] var={-11,11,-11,11,11,11,-9}; int largest = 0; int secLargest = 0; if(var.length == 1) { largest = var[0]; secLargest = var[0]; } else if(var.length > 1){ largest= var[0]; secLargest = var[1]; for(int i=1;ilargest) { secLargest = largest; largest = var[i]; } else if(var[i]>secLargest && var[i] != largest) { secLargest= var[i]; } } else{ if(var[i]>largest) { secLargest = largest; largest = var[i]; } else { secLargest = var[i]; } } } } System.out.println("Largest: "+largest+" Second Largest: "+secLargest); } }
Devansh
          public static void main(String[] args) { int arr[] = { -5, 4, 3, 2, 1}; int largest = arr[0]; int secondLargest = arr[1]; System.out.println("The given array is:" ); for (int i = 0; i < arr.length; i++) { System.out.print(arr[i]+"\t"); } for (int i = 1; i < arr.length; i++) { if (arr[i] > largest) { secondLargest = largest; largest = arr[i]; } else if (arr[i] > secondLargest) { secondLargest = arr[i]; } } System.out.println("\nSecond largest number is:" + secondLargest); } }
SHRIDHAR M PATIL
         package com.shree.basicprograms; import java.awt.DisplayMode; import java.util.Scanner; public class ArrayClass { public static int[] readArray() { Scanner sc = new Scanner(System.in); System.out.println("Enter the Size of array"); int n = sc.nextInt(); System.out.println("Enter " + n + " Elements"); int[] ar = new int[n]; for (int i = 0; i < n; i++) { ar[i] = sc.nextInt(); } return ar; } public static void display(int[] array) { for (int i = 0; i < array.length; i++) { System.out.print(array[i] + " "); } System.out.println(); } public static void main(String[] args) { int[] a=readArray(); display(a); int fbig=a[0],sbig=a[1]; for (int i = 1; i < a.length; i++) { if(a[i]>fbig) { sbig=fbig; fbig=a[i]; } else if(a[i]>sbig) { sbig=a[i]; } } System.out.println("First big "+fbig); System.out.println("Second big "+sbig); } }

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