## Strings

A string in Matlab is merely a character row vector the size of which is the number of characters. Entering a string may be done using a sequence of characters surrounded by apostrophes.

```>> strHW = 'Hello World!'

strHW =

Hello World!

>> size( strHW )

ans =

1     12

```

You may turn a character array into a standard Matlab array by calling the function double:

```double( strHW )

>> double( strHW )

ans =

72   101   108   108   111    32    87   111   114   108   100    33

```

Converting a row vector v to a string does mod(floor(v), 256) and then converts each value to its ascii character equivalent.

To create a string containing an apostrophe, use a pair of apostrophes:

```>> 'Winston''s home page'

ans =

Winston's home page

```

Other functions:

Function Description
ischar(s) returns 1 if s is a character array, 0 otherwise.
isletter(s) returns a logical 0-1 array of the same size as the string s, with an entry 1 if the corresponding entry in s is a letter (a-z, A-Z) and 0 otherwise
isspace(s) returns a logical 0-1 array of the same size as the string s, with an entry 1 if the corresponding entry in s is either a spaces, newlines, carriage returns, tabs, vertical tabs, or formfeeds, and 0 otherwise
lower(s) converts each lower case letter in s to upper case
upper(s) converts each upper case letter in s to lower case
strjust(s) change the justification (white space on either side) of the string s
findstr(s, t) returns a vector of each occurence of the string t in s
strcmp(s, t) returns 1 if the strings s and t are the same and 0 otherwise
strncmp(s, t, n) returns 1 if the first n charcters of the strings s match the first n characters of t and 0 otherwise
strrep(s, t, u) replaces all occurences of the string t in the string s with the string u