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 section Arithmetic Operators) 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 section Numeric Data Types, for more information about creating matrices.

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