| A single character of: a, b or c | Matches either an a, b or c character | [abc] | Common tokens |
| A character except for: a, b or c | Matches any character except for an a, b or c | [^abc] | Common tokens |
| A character in the range: a-z | Matches any characters between a and z, including a and z. | [a-z] | Common tokens |
| A character not in the range: a-z | Matches any characters except those in the range a-z. | [^a-z] | Common tokens |
| A character in the range: a-z or A-Z | Matches any characters between a-z or A-Z. You can combine as much as you, please. | [a-zA-Z] | Common tokens |
| Any single character | Matches any character other than newline (or including line terminators with the /s flag) | . | Common tokens |
| Alternate - match either a or b | Matches either what is before the | or what is after it - in this case `a` or `b`. | a|b | Common tokens |
| Any whitespace character | Matches any space, tab or newline character. | \s | Common tokens |
| Any non-whitespace character | Matches anything other than a space, tab or newline. | \S | Common tokens |
| Any digit | Matches any decimal digit. Equivalent to [0-9]. | \d | Common tokens |
| Any non-digit | Matches anything other than a decimal/digit. | \D | Common tokens |
| Any word character | Matches any letter, digit or underscore. Equivalent to [a-zA-Z0-9_]. | \w | Common tokens |
| Any non-word character | Matches anything other than a letter, digit or underscore. Equivalent to [^a-zA-Z0-9_] | \W | Common tokens |
| Match everything enclosed | A non-capturing group allows you to apply quantifiers to part of your regex but does not capture/assign an ID. | (?:...) | Common tokens |
| Capture everything enclosed | Isolates part of the full match to be later referred to by ID within the regex or the matches array. IDs start at 1. | (...) | Common tokens |
| Zero or one of a | Matches an `a` character or nothing. | a? | Common tokens |
| Zero or more of a | Matches zero or more consecutive `a` characters. | a* | Common tokens |
| One or more of a | Matches one or more consecutive `a` characters. | a+ | Common tokens |
| Exactly 3 of a | Matches exactly 3 consecutive `a` characters. | a{3} | Common tokens |
| 3 or more of a | Matches at least 3 consecutive `a` characters. | a{3,} | Common tokens |
| Between 3 and 6 of a | Matches between 3 and 6 (inclusive) consecutive `a` characters. | a{3,6} | Common tokens |
| Start of string | Matches the start of a string without consuming any characters. If /m multiline mode is used, this will also match immediately after a newline character. | ^ | Common tokens |
| End of string | Matches the end of a string without consuming any characters. If multiline mode is used, this will also match immediately before a newline character. | $ | Common tokens |
| A word boundary | Matches, without consuming any characters, immediately between a character matched by \w and a character not matched by \w (in either order). It cannot be used to separate non words from words. | \b | Common tokens |
| Non-word boundary | Matches, without consuming any characters, at the position between two characters matched by \w. | \B | Common tokens |
| Newline | Matches a newline character | \n | General tokens |
| Carriage return | Matches a carriage return, unicode character U+2185. | \r | General tokens |
| Tab | Matches a tab character. Historically, tab stops happen every 8 characters. | \t | General tokens |
| Null character | Matches a null character, most often visually represented in Unicode using U+2400. | \0 | General tokens |
| Positive Lookahead | Asserts that the given subpattern can be matched here, without consuming characters | (?=...) | Group Constructs |
| Negative Lookahead | Starting at the current position in the expression, ensures that the given pattern will not match. Does not consume characters. | (?!...) | Group Constructs |
| Positive Lookbehind | Ensures that the given pattern will match, ending at the current position in the expression. The pattern must have a fixed width. Does not consume any characters. | (?<=...) | Group Constructs |
| Negative Lookbehind | Ensures that the given pattern would not match and end at the current position in the expression. The pattern must have a fixed width. Does not consume characters. | (?<!...) | Group Constructs |