how to append character at any position in stringbuilder
The java.lang.StringBuilder.insert(int offset, char c) method inserts the
string representation of the char argument into this sequence.
The second argument is inserted into the contents of this
sequence at the position indicated by offset.
The length of this sequence increases by one.
The offset argument must be greater than or equal to 0, and less than
or equal to the length of this sequence.
________________________________________________
public StringBuilder insert(int offset, char c)
________________________________________________
Example:-
StringBuilder str = new StringBuilder("Jinal Patel");
System.out.println("string = " + str);
// insert character value at offset 8
str.insert(8, 'h');