The dollar character $ in a regular expression only matches at the end of the input, or (for multi-line regular expressions) at the end of a line. If it is followed by a pattern that must match a non-empty sequence of (non-newline) input characters, it cannot possibly match, rendering the entire regular expression unmatchable.

Examine the regular expression to find and correct any typos.

In the following example, the regular expression /\.\(\w+$\)/ cannot match any string, since it contains a dollar assertion followed by an escape sequence that matches a closing parenthesis.

  • Mozilla Developer Network: JavaScript Regular Expressions.
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