translate()

Description

translate() scans each character of string and replaces it according to a character mapping defined by from and to. For each character at position i in from, the corresponding character at position i in to is its replacement. If a character appears in from but to is shorter (i.e. there is no character at the same position in to), the character is deleted from the output.

Characters not present in from are copied unchanged.

This makes translate() the XPath 1.0 tool for:

• Converting case (e.g. uppercase to lowercase) without processor extensions.
• Removing unwanted characters (digits, punctuation, control characters).
• Simple one-to-one character substitutions.

For pattern-based replacement, use replace() in XSLT 2.0+.

Parameters

Return value

xs:string — the transformed string with characters replaced or removed.

Examples

Convert to lowercase (ASCII only)

Input XML:

<?xml version="1.0" encoding="UTF-8"?>
<labels>
  <label>HELLO WORLD</label>
  <label>Mixed Case Text</label>
</labels>

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

  <xsl:variable name="upper" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'"/>
  <xsl:variable name="lower" select="'abcdefghijklmnopqrstuvwxyz'"/>

  <xsl:template match="/labels">
    <results>
      <xsl:for-each select="label">
        <lower><xsl:value-of select="translate(., $upper, $lower)"/></lower>
      </xsl:for-each>
    </results>
  </xsl:template>
</xsl:stylesheet>

Output:

<results>
  <lower>hello world</lower>
  <lower>mixed case text</lower>
</results>

Remove non-numeric characters

Input XML:

<?xml version="1.0" encoding="UTF-8"?>
<phones>
  <phone>(555) 123-4567</phone>
  <phone>+1 800 555 0199</phone>
</phones>

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/phones">
    <digits-only>
      <xsl:for-each select="phone">
        <phone>
          <xsl:value-of select="translate(., '() +-', '')"/>
        </phone>
      </xsl:for-each>
    </digits-only>
  </xsl:template>
</xsl:stylesheet>

Output:

<digits-only>
  <phone>5551234567</phone>
  <phone>18005550199</phone>
</digits-only>

Notes

• If a character appears more than once in from, the first occurrence defines the mapping; subsequent occurrences are ignored.
• When to is the empty string "", every character in from is deleted from the output.
• translate() operates on individual code points, not substrings. It cannot replace multi-character sequences. Use replace() (XSLT 2.0+) for substring replacement.
• The ASCII case-folding technique (translate(., 'ABC...', 'abc...')) does not handle accented or non-Latin characters. For full Unicode case conversion in XSLT 2.0+, use lower-case() or upper-case().

See also

• normalize-space()
• contains()
• replace() — requires XSLT 2.0+