Method codePointBefore

lib/java/lang/String.java:1875–1881

Retrieves the Unicode code point value that precedes the specified index. @param index the index to the char code unit within this string. @return the Unicode code point value. @throws IndexOutOfBoundsException if index is less than 1 or greater than

(int index)

     * @since 1.5
     */
    public int codePointBefore(int index) {
        if (index < 1 || index > count) {
            throw new IndexOutOfBoundsException();
        }
        int s = index + offset;
        return Character.codePointBefore(value, s);
    }

    /**
     * Calculates the number of Unicode code points between {@code beginIndex}