The character at the specified index is set to ch. This sequence is altered to represent a new character sequence that is identical to the old character sequence, except that it contains the character ch at position index.

The index argument must be greater than or equal to 0, and less than the length of this sequence.

Parameters:

index		the index of the character to modify.
ch		the new character.

Exceptions:

IndexOutOfBoundsException

if index is negative or greater than or equal to length().