If you want to look at all the special characters that can be used in regular expressions in a single table, see the following: Special characters in regular expressions. Unicode property escapesĭistinguish based on unicode character properties, for example, upper- and lower-case letters, math symbols, and punctuation. Indicate numbers of characters or expressions to match. Indicate groups and ranges of expression characters. For example, distinguishing between letters and digits. Character classesĭistinguish different types of characters. AssertionsĪssertions include boundaries, which indicate the beginnings and endings of lines and words, and other patterns indicating in some way that a match is possible (including look-ahead, look-behind, and conditional expressions). The following pages provide lists of the different special characters that fit into each category, along with descriptions and examples. In the string "cbbabbbbcdebc", this pattern will match the substring "abbbbc". When the search for a match requires something more than a direct match, such as finding one or more b's, or finding white space, you can include special characters in the pattern.įor example, to match a single "a" followed by zero or more "b"s followed by "c", you'd use the pattern /ab*c/: the * after "b" means "0 or more occurrences of the preceding item."
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