Strings - Untitled
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## 5 Strings

A string constant consists of a sequence of characters enclosed in either double-quote or single-quote marks. For example, both of the following expressions

         "parrot"
         'parrot'

represent the string whose contents are ‘`parrot`’. Strings in Octave can be of any length.

Since the single-quote mark is also used for the transpose operator (see Arithmetic Ops) but double-quote marks have no other purpose in Octave, it is best to use double-quote marks to denote strings.

In double-quoted strings, the backslash character is used to introduce escape sequences that represent other characters. For example, ‘`\n`’ embeds a newline character in a double-quoted string and ‘`\"`’ embeds a double quote character.

In single-quoted strings, backslash is not a special character.

Here is an example showing the difference

         toascii ("\n")
              10
         toascii ('\n')
              [ 92 110 ]

You may also insert a single quote character in a single-quoted string by using two single quote characters in succession. For example,

         'I can''t escape'
              I can't escape

Here is a table of all the escape sequences used in Octave. They are the same as those used in the C programming language.

`\\`
  Represents a literal backslash, ‘`\`’.
`\"`
  Represents a literal double-quote character, ‘`"`’.
`\'`
  Represents a literal single-quote character, ‘`'`’.
`\0`
  Represents the “nul” character, control-@, ASCII code 0.
`\a`
  Represents the “alert” character, control-g, ASCII code 7.
`\b`
  Represents a backspace, control-h, ASCII code 8.
`\f`
  Represents a formfeed, control-l, ASCII code 12.
`\n`
  Represents a newline, control-j, ASCII code 10.
`\r`
  Represents a carriage return, control-m, ASCII code 13.
`\t`
  Represents a horizontal tab, control-i, ASCII code 9.
`\v`
  Represents a vertical tab, control-k, ASCII code 11.

Strings may be concatenated using the notation for defining matrices. For example, the expression

         [ "foo" , "bar" , "baz" ]

produces the string whose contents are ‘`foobarbaz`’. See Numeric Data Types, for more information about creating matrices.