java - Array index out of bounds -

although tried solve exception using break still fails on input "321". code bubble sort on hackerrank.

the error occurs on if(a[i+1]==n).

import java.io.*;`` import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*;  public class solution {  public static void main(string[] args) {     scanner in = new scanner(system.in);     int n = in.nextint();     int[] = new int[n];     for(int a_i=0; a_i < n; a_i++){         a[a_i] = in.nextint();     }     // write code here     int numswaps=0;     for(int i=0;i<n;i++){         if(a[i+1]==n){       // error occurs here             break;         }         else{                 if(a[i]>a[i+1]){                 int temp=a[i];                 a[i]=a[i+1];                 a[i+1]=temp;                 numswaps++;                 }             }     }     //firstelement=a[0];     //lastelement=a[n-1];     system.out.println("array sorted in"+" "+numswaps+" "+"swaps."+"\n"+"first element:"+" "+a[0]+"\n"+"last element:"+" "+a[n-1]); } 

}

your condition i<n overflow when i=n-1, because adding i+1, referencing array out-of-bounds.

the fix easy, however, change condition i<n-1.

import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*;  public class solution {     public static void main(string[] args) {         scanner in = new scanner(system.in);         int n = in.nextint();         int[] = new int[n];         for(int a_i=0; a_i < n; a_i++){             a[a_i] = in.nextint();         }         // write code here         int numswaps=0;         for(int i=0;i<n-1;i++){             if(a[i+1]==n){                 break;             } else if(a[i]>a[i+1]){                 int temp=a[i];                 a[i]=a[i+1];                 a[i+1]=temp;                 numswaps++;             }         }         //firstelement=a[0];         //lastelement=a[n-1];         system.out.println("array sorted in"+" "+numswaps+" "+"swaps."+"\n"+"first element:"+" "+a[0]+"\n"+"last element:"+" "+a[n-1]); } 

also, take bit of pride in code style; did couple touch-ups, far clean.