来看看。。。。。。

CHAR Create character array (string).
    S = CHAR(X) converts the array X that contains nonnegative integers
    representing character codes into a MATLAB character array (the first
    127 codes are ASCII). The actual characters displayed depends on the
    character encoding scheme for a given font.  The result for any
    elements of X outside the range from 0 to 65535 is not defined (and
    may vary from platform to platform).  Use DOUBLE to convert a
    character array into its numeric codes.

STRINGS Character strings in MATLAB.
    S = 'Any Characters' creates a character array, or string. The
    string is actually a vector whose components are the numeric codes
    for the characters (the first 127 codes are ASCII). The actual
    characters displayed depends on the character set encoding for a
    given font. The length of S is the number of characters. A quote
    within the string is indicated by two quotes.