For reference, this is what String.substring(int, int) does[1] in Java: public String substring(int beginIndex, int endIndex) { int length = length

For reference, this is what String.substring(int, int) does[1] in Java: public String substring(int beginIndex, int endIndex) { int length = length(); checkBoundsBeginEnd(beginIndex, endIndex, length); ... Where checkBoundsBeginEnd[2] does: static void checkBoundsBeginEnd(int begin, int end, int length) { if (begin < 0 || begin > end || end > length) { throw new StringIndexOutOfBoundsException( "begin " + begin + ", end " + end + ", length " + length); } } (as it should, in my opinion). [1] https://github.com/AdoptOpenJDK/openjdk-jdk11/blob/f0ef2826d2116f4e0c0ed21f8d54fe9d0706504e/src/java.base/share/classes/java/lang/String.java#L1872-L1881 https://github.com/AdoptOpenJDK/openjdk-jdk11/blob/f0ef2826d... [2] https://github.com/AdoptOpenJDK/openjdk-jdk11/blob/f0ef2826d2116f4e0c0ed21f8d54fe9d0706504e/src/java.base/share/classes/java/lang/String.java#L3317-L3322 https://github.com/AdoptOpenJDK/openjdk-jdk11/blob/f0ef2826d...