builtins.md

Built-in Functions for Strings

The functions sprintf and sscanf will be presented in their own sections, below.

• Check if it is a string

  stringp(*something*)

  The function stringp returns 1 if the value something is a string, otherwise 0.

• Finding the size

  sizeof(*string*)
  

  or

  strlen(*string*)

  Returns the length (that is, the number of characters) in the string string.

  sizeof("hi ho")
  

  gives the result

  5
  

  .

  sizeof("")
  

  gives the result

  0
  

  .

  The function strlen is a synonym for

  sizeof
  

  .

• Reversing a string

  reverse(*string*)
  

  returns a new string with the characters in reverse order.

  reverse("foo")
  

  gives the result

  "oof"
  

  .

• Replacing parts in a string

  replace(*string*, *old*, *new*)
  

  returns a new string where all occurrences of the string old have been replaced with the string new:

  replace("fooFOOfoo", "foo", "fum")
  

  gives the result

  "fumFOOfum"
  

  .

• Converting to lower case

  lower_case(*string*)
  

  returns a new string where all upper-case characters in the string string have been turned to lower case:

  lower_case("A Foo IS!")
  

  gives the result

  "a foo is!"
  

  .

• Converting to upper case

  upper_case(*string*)
  

  returns a new string where all lower-case characters in the string string have been turned to upper case:

  upper_case("A Foo IS!")
  

  gives the result

  "A FOO IS!"
  

  .

• Capitalizing

  String.capitalize(*string*)

  If the first character in the string string is a lower-case character, it is converted to upper case:

  String.capitalize("xyz-Foo")

  gives the result

  "Xyz-Foo"
  

  .

• Finding a substring in a string

  search(*haystack*, *needle*)
  

  returns the index of the start of the first occurrence of the string needle in the string haystack:

  search("sortohum", "orto")
  

  gives the result

  1
  

  .