concat() Returns the concatenation of all its arguments.
contains() Returns true if the second string is contained within the first string, otherwise it returns false.
starts-with() Returns true if the first string starts with the second string, otherwise it returns false.
string() Converts the value argument to a string.
string-length() Returns the number of characters in a string.
substring() Returns a part of the string in the string argument.
substring-after() Returns the part of the string in the string argument that occurs after the substring in the substr argument.
substring-before() Returns the part of the string in the string argument that occurs before the substring in the substr argument.
translate() Takes the value argument and replaces all occurrences of string1 with string2 and returns the modified string.