java - android change first blank to "AA" -

change first blank "aa"

string = "a b c"; 

change

string = "aaab c"; 

the answer clear

a = a.replacefirst(" ", "aa"); 

try code,you may got expected answer,

string str="a b c";     boolean a1 = true ;      stringbuilder strbu = new stringbuilder();     for(int i=0 ; i<str.length();i++)     {            character b = str.charat(i);         if(b.equals(' ') && a1 == true )         {             a1 = false;             strbu = strbu.append("aa");         }         else         {             strbu = strbu.append(b);         }     }     log.e("str","string:"+strbu.tostring());