java - Checking for decimal after 10 digits - substring(i,1) not working -

i have 2 problems:

1. x.substring(i,1) breaks in try/catch

2. because of , possibly other things, can't method work. i'm trying have when user enters decimal, increase max length of edittext, decrease max length original max length if user enters number large.

   boolean toobig = false; edittext txt = (edittext)findviewbyid(r.id.num1); textview display = (textview)findviewbyid(r.id.display); string x = txt.gettext().tostring(); // string in edittext string str = "didn't work"; try {     if (x.contains("."))      {         // set max length 15         if (x.length() >= 10)         {             // see if decimal contained after 10 digits             (int = 10; < x.length(); i++)             {                 str = x.subtring(i,1); // breaks here (test)                 if (x.substring(i,1).equals(".")) // breaks here                 {                     toobig = true;                 }             }         }          if (toobig)         {             // set text blank , max length 8         }     } } catch (exception e)  {     txt.settext(str); // "didn't work" } 

what can fix x.substring(i,1) problem?

you have change (i,1) (i, i+1) because in java, second number index end point, not "how many characters go for", in other languages. start @ i, , end @ 1 more i.

you use indexof(".") solve problem instead. also, have else statement change max length original max length in case user erases decimal.

change try this:

if (x.contains("."))  {     // set max length 15      if (x.indexof(".") > 9)     {         txt.settext(x.substring(0,9));            // set length 9     } } else {     // set max length original }