StringIndexOutOfBoundException

Question

Hi I was just using stringbuilder to obtain certain part of the string using substring(int start, int end).. but I\'m having this error

08-17 20:27:40.737: E         


        

Answer 1

I just want to obtain the first 4 string of my phoneNumber string

But your number has length lower than 4. If you want to get first four numbers you need to add simple condition:

if (str.length() > 4) {
   // do your work
}

Don't forget that substring begins at the specified start and extends to the character at index end - 1.

Answer 2

Are you using the substring() method but you no has length lower than 4 ,so if you want to get only four number use the following code.

Ex:

   class  SubString
      {
public static void main(String[] args) 
{
StringBuilder str = new StringBuilder(phoneNumber);
    if(str.length()>4){
    System.out.println(str.substring(0,4));
    }
     }
    }