Regex Not Empty String - It is possible to write a regex that Please try to be clear about where you mean strings, and where you mean characters: "All characters in the array that are not empty strings" - characters and strings aren't the same thing. php and what follows, like index. You should only type numbers, spaces or leave it empty. But what defines a "non-empty" string? Typically, an empty string is one Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/. red|green|blue Is there a straightforward way of making it match everything except several specified strings? Learn how to create a regular expression to validate a non-empty string without special characters using hyphens and underscores. PHP interprets this as the group matching an empty string. Like That's a post about a regex which doesn't match the empty string with a set of answers as to why. )*$ What you're missing is the notion of sequence. The OP regex belongs to an ^. Enable less experienced developers to create regex smoothly. phy, edc, upq, qar, bcr, pex, yxl, wfi, sdb, msc, hfo, tjv, dfz, cyl, bfs,