static int lastIndexOf()

in src/main/java/org/apache/commons/lang3/CharSequenceUtils.java [150:215]
58 lines of code
20 McCabe index (conditional complexity)

    static int lastIndexOf(final CharSequence cs, final CharSequence searchChar, int start) {
        if (searchChar == null || cs == null) {
            return NOT_FOUND;
        }
        if (searchChar instanceof String) {
            if (cs instanceof String) {
                return ((String) cs).lastIndexOf((String) searchChar, start);
            }
            if (cs instanceof StringBuilder) {
                return ((StringBuilder) cs).lastIndexOf((String) searchChar, start);
            }
            if (cs instanceof StringBuffer) {
                return ((StringBuffer) cs).lastIndexOf((String) searchChar, start);
            }
        }

        final int len1 = cs.length();
        final int len2 = searchChar.length();

        if (start > len1) {
            start = len1;
        }

        if (start < 0 || len2 > len1) {
            return NOT_FOUND;
        }

        if (len2 == 0) {
            return start;
        }

        if (len2 <= TO_STRING_LIMIT) {
            if (cs instanceof String) {
                return ((String) cs).lastIndexOf(searchChar.toString(), start);
            }
            if (cs instanceof StringBuilder) {
                return ((StringBuilder) cs).lastIndexOf(searchChar.toString(), start);
            }
            if (cs instanceof StringBuffer) {
                return ((StringBuffer) cs).lastIndexOf(searchChar.toString(), start);
            }
        }

        if (start + len2 > len1) {
            start = len1 - len2;
        }

        final char char0 = searchChar.charAt(0);

        int i = start;
        while (true) {
            while (cs.charAt(i) != char0) {
                i--;
                if (i < 0) {
                    return NOT_FOUND;
                }
            }
            if (checkLaterThan1(cs, searchChar, len2, i)) {
                return i;
            }
            i--;
            if (i < 0) {
                return NOT_FOUND;
            }
        }
    }