@Override
public char charAt (int index)

Implementing: java.lang.CharSequence

Returns the char value in this sequence at the specified index. The first char value is at index 0, the next at index 1, and so on, as in array indexing.

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

If the char value specified by the index is a surrogate, the surrogate value is returned.

Parameters:
index    the index of the desired char value.

Returns:  the char value at the specified index.