info octave

A.1.3 Character Strings in Oct-Files

In Octave a character string is just a special Array class. Consider the example

An example of the use of this function is

s0 = ["First String"; "Second String"];
[s1,s2] = stringdemo (s0)
⇒ s1 = Second String
        First String

⇒ s2 = First String
        Second String

typeinfo (s2)
⇒ sq_string
typeinfo (s1)
⇒ string

One additional complication of strings in Octave is the difference between single quoted and double quoted strings. To find out if an octave_value contains a single or double quoted string an example is

    if (args(0).is_sq_string ())
      octave_stdout << 
        "First argument is a singularly quoted string\n";
    else if (args(0).is_dq_string ())
      octave_stdout << 
        "First argument is a doubly quoted string\n";

Note however, that both types of strings are represented by the charNDArray type, and so when assigning to an octave_value, the type of string should be specified. For example

octave_value_list retval;
charNDArray c;
…
// Create single quoted string
retval(1) = octave_value (ch, true, '\'');

// Create a double quoted string
retval(0) = octave_value (ch, true);