unescaping

Unescaping is the process of converting escaped sequences in a text back into their literal characters. It is the inverse operation of escaping, which encodes characters to ensure safe or convenient representation in a given context. Unescaping is used when the data must be interpreted or displayed in its original form.

Common contexts include programming languages, data formats, and communication protocols. In many languages, escape sequences begin with a backslash and represent control characters (for example, in C and JavaScript: \n becomes a newline, \t a tab, \\ a literal backslash). Unicode escapes such as \uXXXX or \UXXXXXXXX encode non‑ASCII characters. URL or percent encoding uses percent signs followed by hex digits (for example %3C represents '<'); unescaping decodes these back to the original characters. HTML and XML use named entities (&amp; -> &, &lt; -> <) or numeric references (&#65; -> 'A').

Examples: the string \n unescapes to a newline character; \u0041 unescapes to the letter 'A'; the URL fragment %2Fpath%2Fto%2Ffile unescapes to /path/to/file; the HTML entity &nbsp; unescapes to a non-breaking space.

Implementation and considerations: many languages provide library support for unescaping, such as JSON parsers decoding escape sequences, URL decoders, or HTML parsers. Unescaping can introduce security risks if input is processed without validation, including double decoding or path traversal in file-name or URL contexts. It is important to apply unescaping only where appropriate and to rely on established library routines for correctness and safety.