regexSwap() : Replace Using Regular Expression

Summary

Replace all occurrences matching a regular expression pattern with a replacement string.

Signature

regexSwap(str, pattern, replacement)

Parameters

Returns

Type: String

The string with all pattern matches replaced.

Examples

Remove All Digits

<p>{{regexSwap(model.text, '\\d', '')}}</p>

Data:

doc.Params["model"] = new {
    text = "Product ABC123 costs $45.99"
};

Output:

<p>Product ABC costs $.</p>

Mask Phone Numbers

<p>{{regexSwap(model.phone, '\\d', 'X')}}</p>

Data:

doc.Params["model"] = new {
    phone = "555-123-4567"
};

Output:

<p>XXX-XXX-XXXX</p>

Replace Multiple Spaces

<p>{{regexSwap(model.text, '\\s+', ' ')}}</p>

Data:

doc.Params["model"] = new {
    text = "Too    many     spaces"
};

Output:

<p>Too many spaces</p>

Sanitize Special Characters

<p>{{regexSwap(model.filename, '[^a-zA-Z0-9_.-]', '_')}}</p>

Data:

doc.Params["model"] = new {
    filename = "My File (2024)!.pdf"
};

Output:

<p>My_File__2024__.pdf</p>

Format Numbers with Separators

<p>{{regexSwap(model.number, '(\\d)(?=(\\d{3})+$)', '$1,')}}</p>

Remove HTML Tags

<p>{{regexSwap(model.html, '<[^>]+>', '')}}</p>

Data:

doc.Params["model"] = new {
    html = "<strong>Bold</strong> and <em>italic</em> text"
};

Output:

<p>Bold and italic text</p>

Convert Dates

<!-- Convert MM/DD/YYYY to YYYY-MM-DD -->
<p>{{regexSwap(model.date, '(\\d{2})/(\\d{2})/(\\d{4})', '$3-$1-$2')}}</p>

Data:

doc.Params["model"] = new {
    date = "03/15/2024"
};

Output:

<p>2024-03-15</p>

Notes

• Uses .NET regex syntax
• Replaces all occurrences (not just first)
• Backslashes must be escaped: \\d, \\w, etc.
• Supports capture groups: $1, $2, etc.
• For simple replacement, replace() is faster
• More powerful but slower than replace()
• Returns original string if pattern doesn’t match

Common Patterns

See Also

• regexIsMatch Function
• regexMatches Function
• replace Function