Programming PHP, 3rd Edition

Name

version_compare

Synopsis

mixed version_compare(string one, string two[, string operator])

Compares two version strings and returns −1 if one is less than two, 0 if they are equal, and 1 if one is greater than two. The version strings are split into each numeric or string part, then compared as string_value < "dev" < "alpha" or "a" < "beta" or "b" < "rc" < numeric_value < "pl" or "p".

If operator is specified, the operator is used to make a comparison between the version strings, and the value of the comparison using that operator is returned. The possible operators are < or lt; <= or le; > or gt; >= or ge; ==, =, or eq; and !=, <>, and ne.