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5.1 Escape Sequences in String Constants

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 ]

Here is a table of all the escape sequences used in Octave (within double quoted strings). 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.

In a single-quoted string there is only one escape sequence: you may insert a single quote character using two single quote characters in succession. For example,

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

In scripts the two different string types can be distinguished if necessary by using is_dq_string and is_sq_string.

Built-in Function: is_dq_string (x)

Return true if x is a double-quoted character string.

See also: is_sq_string, ischar.

Built-in Function: is_sq_string (x)

Return true if x is a single-quoted character string.

See also: is_dq_string, ischar.


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