A version string has three components: The version number itself, an optional pre-release version, and an optional build version. Each component is a sequence of tokens; each token is either a non-negative integer or a string. Tokens are separated by the punctuation characters '.', '-', or '+', or by transitions from a sequence of digits to a sequence of characters that are neither digits nor punctuation characters, or vice versa. Consecutive repeated punctuation characters are treated as a single punctuation character.

• The version number is a sequence of tokens separated by '.' characters, terminated by the first '-' or '+' character.
• The pre-release version is a sequence of tokens separated by '.' or '-' characters, terminated by the first '+' character.
• The build version is a sequence of tokens separated by '.', '-', or '+' characters.

When comparing two version strings, the elements of their corresponding components are compared in pointwise fashion. If one component is longer than the other, but otherwise equal to it, then the first component is considered the greater of the two; otherwise, if two corresponding elements are integers then they are compared as such; otherwise, at least one of the elements is a string, so the other is converted into a string if it is an integer and the two are compared lexicographically. Trailing integer elements with the value zero are ignored.

Given two version strings, if their version numbers differ then the result of comparing them is the result of comparing their version numbers; otherwise, if one of them has a pre-release version but the other does not then the first is considered to precede the second, otherwise the result of comparing them is the result of comparing their pre-release versions; otherwise, the result of comparing them is the result of comparing their build versions.