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A series of characters. This isn't really a class, as suggested by its lower-case name. Parameters of type string pass by value, unlike all variables of real object types, which pass by reference. Instead, this is just a pseudo-class which provides convenience methods on instances of strings. The other pseudo-class is int.

[edit] Methods

compare(string s) : int	Compare one string with another. Returns a negative number if s is alphabetically before the subject, positive if greater or zero if the two are equal. Note that this function currently does a simple ASCII compare, not a proper unicode-aware sort.
contains(string sub) : bool	Return true if string contains sub
css_keyword() : string	Returns the string if it is syntactically valid as a CSS keyword (only letters and spaces), else returns an empty string.
css_keyword(string[] allowed) : string	Same as string.css_keyword() except also imposes a whitelist of valid keywords given in allowed.
css_keyword_list() : string	Analyses the string as a space-separated list of CSS keywords and returns a string containing the items that are syntactically acceptable.
css_keyword_list(string[] allowed) : string	Same as string.css_keyword_list() except also imposes a whitelist of valid keywords given in allowed.
css_length_value() : string	If the string contains a valid CSS length value, returns a canonical version. Else returns an empty string.
css_string() : string	Returns the string escaped and quoted as a CSS string literal, safe for insertion into a stylesheet.
css_url_value() : string	If the string contains a valid HTTP or HTTPS URL it is returned. Otherwise, an empty string is returned.
ends_with(string sub) : bool	Returns true if string ends in sub
length() : int	Return the number of characters in the string.
lower() : string	Returns string in lower case.
repeat(int n) : string	Returns the string repeated n times
starts_with(string sub) : bool	Returns true if string begins with sub
substr(int start, int length) : string	Returns up to length characters from string, skipping start characters from the beginning.
upper() : string	Returns string in upper case
upperfirst() : string	Return string with the first character capitalized.