Method setCharAt

lib/java/lang/AbstractStringBuilder.java:518–527

Sets the character at the index. @param index the zero-based index of the character to replace. @param ch the character to set. @throws IndexOutOfBoundsException if index is negative or greater than or equal to the current {@link #length

(int index, char ch)

     *             current {@link #length()}.
     */
    public void setCharAt(int index, char ch) {
        if (0 > index || index >= count) {
            throw new StringIndexOutOfBoundsException(index);
        }
        if (shared) {
            value = value.clone();
            shared = false;
        }
        value[index] = ch;
    }

    /**
     * Sets the current length to a new value. If the new length is larger than