# Second Smallest Number in an Array in Java

By sorting the arrays and returning the second element, we can use Java to discover the second-smallest number in the array.

``````Input:  arr[] = {10, 11, 13, 15, 34, 51}
Output: The smallest element is 10 and
The second smallest element is 11
``````

### Method 1: By sorting the array using the sort function

SecondSmallest1.java

``````// Public class declaration
import java.io.*;
import java.util.*;
public class SecondSmallest1
{
// public static method is used
// static methods can be implemented without the creation of Objects
public static int secondSmallest(int [ ]  arr ,int n ) {
// Sorting the algorithm using the sort function
Arrays.sort(arr);
System.out.println( ) ;
System.out.println("After sorting the elements are");
for(int i = 0 ; i < n ; i++ )
{
System.out.print(arr[ i ] + " ") ;
}
System.out.println( );
//2nd smallest element is present at index 1 because the index starts from 0
// returning the seconds element
return arr ;
}
// Main section of the program where execution starts
public static void main (String s[ ])
{
//  input array declaration and initialization in a static way
int inputarray1[ ] = { 11,12,25,36,63, 52 };
int inputarray2[ ] = { 424  166  9, 177  233,212  515 } ;
// storing the length of the array into integer variable n1
int n1 = inputarray1.length ;
// storing the length of the array into integer variable n2
int n2 = inputarray2.length ;
System.out.println (" First array elements before sorting are " ) ;
// printing the total array
for(int i = 0 ; i < n1 ; i++ )
{
// printing each element
System.out.print(inputarray1[ i ] + " " ) ;
}
System.out.println( " Second smallest element is : "+ secondSmallest ( inputarray1 , n1 ) ) ;
System.out.println( " Second  array elements before sorting are " ) ;
// printing the array elements
for(int i = 0 ; i < n1 ; i++ )
{
// printing each element of the array
System.out.print ( inputarray2[ i ] + " " ) ;
}
System.out.println ( ) ;
System.out.println (" Second smallest element is  "+ secondSmallest( inputarray2 , n2 ) ) ;
}}
``````

Output

``````The first array elements before sorting are
11 12 25 36 63 52
After sorting, the elements are
11 12 25 36 52 63
The second smallest element is  12
The second array of elements before sorting is
424 166 9 177 233 212
After sorting, the elements are
9 166 177 212 233 424 515
The second smallest element is: 166
``````

### Method 2: By sorting the array without using the sort built-in function

SecondSmallest2.java

``````// Public class declaration
public class SecondSmallest2
{
// public static method is used
// static methods can be implemented without the creation of Objects
public static int secondSmallest (int [ ], int n ) {
// declaring a temporary variable
int t ;
// Iterating through the array using for loop from the first index
// Sorting the algorithm
for (int j = 0;j < n;j++)
{
// Iterating through the array using for loop from j+1 index
for (int i = j + 1;i < n;i++)
{
// swapping the elements if the first element is greater than the second element
if ( a[j] > a [i])
{
// storing value in a temporary variable and swapping the values
t = a[j] ;
a [j] = a [i] ;
a [i] = t ;
}
}
}
//2nd smallest  element is present at index 1 because the index starts from 0
return a  ;
}
// Main section of the program where execution starts
public static void main (String s [ ])
{
// array initialization and declaration
// taking input arrays in a static way
int inputarray1 [ ] = { 11, 12, 25, 36, 63, 52 } ;
int inputarray2 [ ] = { 424, 166, 9, 177, 233,212, 515 } ;
// finding the length of the array using the length function for arrays
// storing the length of the array into integer variable n1
int n1 = inputarray1.length ;
// storing the length of the array into integer variable n2
int n2 = inputarray2.length ;
System. out.println(" First array elements are " ) ;
for(int i = 0 ; i < n1 ; i++ )
{
// printing each element of the array
System.out.print( inputarray1 [ i ] + " " ) ;
}
System.out.println( ) ;
// printing the second smallest number
System.out.println( " Second smallest element is : "+ secondSmallest ( inputarray1 , n1 ) ) ;
// printing the second array of elements
System.out.println ( " Second  array elements are " ) ;
for(int i = 0 ; i < n1 ; i++ )
{
// printing each element of the array
System.out.print ( inputarray2[ i ] + " " ) ;
}
System.out.println( ) ;
// printing the second smallest element in the  given array
System.out.println (" Second smallest element is : "+ secondSmallest ( inputarray2 , n2  ) ) ;
}
}
``````

Output

``````The first array elements are
11 12 25 36 63 52
The second smallest element is : 12
The second array of elements are
424 166 9 177 233 212
The second smallest element is : 166
``````

### Method 3: Using Collections

SecondSmallest3.java

``````// scanner class importing packages
import java.util.*;
public class SecondSmallest3
{
// static method declaration, which is used to find the second smallest element in the array
public static int secondSmallest(Integer [] arr, int sum )
{
// converting the provided Integer array into the list by using Array.asList() method
List<Integer> l = Arrays.asList (arr);
// Sorting the collection framework using the Collections. sort() method
Collections.sort(l);
// storing the second value into the variable r
int r = l.get(1);
// returning the result
return r ;
}
// main method of the section from where execution begins
public static void main(String s [] ){
// creating an object for the scanner class to take inputs from the user during run time
Scanner sc = new Scanner(System.in);
System.out.println("Enter size of the first array ");
// enter the array size of the first array
// storing the size into n1 integer variable
int n1 = sc.nextInt ();
// creating an integer array variable for storing the elements in an array
Integer a[] = new Integer[n1];
System.out.println("Enter the first array elements");
// enter the first array of elements
// using for loop to store the array elements into array
for (int i=0;i<n1;i++)
{
a[i] = sc.nextInt ();
}
System.out.println();
System.out.println("Enter size of the second array ");
// enter the size of the second array
// storing the size into integer variable n2
int n2 = sc.nextInt ();
// creating an integer array variable for storing the elements in an array
Integer b[] = new Integer[n2];
System.out.println("Enter the second array elements");
// enter the second array of elements
for (int i=0;i<n2;i++)
{
b[i] = sc.nextInt ();
}
// calling the function and printing it
System.out.println(" Second Smallest element in the first array is "+secondSmallest(a,n1));
System.out.println();
// calling the function and printing it
System.out.println("Second Smallest element in the second array is "+secondSmallest(b,n2));
}}
``````

Output

``````Enter the size of the first array
5
Enter the first array of elements
12 43 12 1 10
Enter the size of the second array
5
Enter the second array of elements
12 23 21 45 33
The second Smallest element in the first array is 10
The second Smallest element in the second array is 21
``````

### Method 4: Using two variables

1) Set the first and second smallest values to be equal to INT MAX

2) Repeat step two for each component.

a) Update the first and second elements if the current element is smaller than the first.

b) Or else, update second if the current element is smaller than it.

SecondSmallest4.java

``````// importing the packages
import java.io.*;
import java.util.*;

class SecondSmallest4
{
/* static method declaration */
/* static method can be used without creating the objects for the class */
static void secondSmallest(int a[])
{
/* declaring and initializing two integer variables */
int f1;
int ans;
int n=a.length;
/* if the size of the array is less than 2, then there will be no second term in the array */
/* so it should print invalid input */
if (n < 2) // checking the size of the array
{
/* printing the invalid input */
System.out.println(" Invalid Input ");
// return statement
return;
}
//initializing the two variables
f1 =  Integer.MAX_VALUE;
ans =  Integer.MAX_VALUE;
for (int j = 0; j < n ; j ++)
{
if (a[j] < f1)
{
ans = f1;
f1 = a[j];
}
else if (a[j] < ans && a[j] != f1 )
ans = a[j];
}
if (ans == Integer.MAX_VALUE)
System.out.println(" No second smallest element int he given array ");
else
System.out.println("The  second Smallest element is " + ans );
}
// Main section of the program, from execution, begins
public static void main (String[] args)
{
Scanner sc=new Scanner(System.in);

System.out.println(" Enter the size of the array");
// variable declaration and initializing it to store the array size
int n1= sc.nextInt();
// array declaration
int a[]=new int[n1];
System.out.println("Enter the array elements ");
// enter the array elements
for(int j=0;j<n1;j++)
{
a[j]=sc.nextInt();
}
// calling the secondSmallest method
secondSmallest(a);
}
}
``````

Output

``````Enter the size of the array
5
Enter the array of elements
12 34 22 66 45
The  second smallest element is 22
``````