You may have notices that I swapped the case of my string, as an example, in the Here document demonstration. That's just the tip of the iceberg - there are a large number of methods that you can run on Ruby strings.


Operators such as + and * work on strings (concatenate and replicate). The % operator is a short form for sprintf, and the << operator is the same as +. You can treat a character string as an array of characters too.

Example:


Note the use of the rand function, used in conjunction with length to choose a random member from an array (and an interesting sweet!). Also note the neat way that we can store a format string in a constant so that we can use it consistently and immutably throughout.



To change case:

 capitalize - first character to upper, rest to lower
 downcase - all to lower case
 swapcase - changes the case of all letters
 upcase - all to upper case

To rejustify:

 center - add white space padding to center string
 ljust - pads string, left justified
 rjust - pads string, right justified

To trim:

 chop - remove last character
 chomp - remove trailing line separators
 squeeze - reduces successive equal characters to singles
 strip - deletes leading and trailing white space

To examine:

 count - return a count of matches
 empty? - returns true if empty
 include? - is a specified target string present in the source?
 index - return the position of one string in another
 length or size - return the length of a string
 rindex - returns the last position of one string in another
 slice - returns a partial string

To encode and alter:

 crypt - password encryption
 delete - delete an intersection
 dump - adds extra \ characters to escape specials
 hex - takes string as hex digits and returns number
 next or succ - successive or next string (eg ba -> bb)
 oct - take string as octal digits and returns number
 replace - replace one string with another
 reverse - turns the string around
 slice! - DELETES a partial string and returns the part deleted
 split - returns an array of partial strings exploded at separator
 sum - returns a checksum of the string
 to_f and to_i - return string converted to float and integer
 tr - to map all occurrences of specified char(s) to other char(s)
 tr_s - as tr, then squeeze out resultant duplicates
 unpack - to extract from a string into an array using a template

To iterate:

 each - process each character in turn
 each_line - process each line in a string
 each_byte - process each byte in turn
 upto - iterate through successive strings (see "next" above)

Let's see the sort of thing we can do with those - reading some data on A roads that's saved on the end of a program into a single string object, then stepping through each of the lines one at a time and extracting information from them. In practise, just the sort of thing that you might want to do!


And here's the sort of output that produces:



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