MATLAB Programming Fundamentals - MathWorks

Required Input Argument

Type

Old Check New Check

(ischar(X) ||

isStringScalar(X)) &&

X ~= ""

Cell array of character

vectors or string array

iscellstr(X) iscellstr(X) ||

isstring(X)

Any text data type ischar(X) ||

iscellstr(X)

ischar(X) ||

iscellstr(X) ||

isstring(X)

Check for Empty Strings

An empty string is a string with no characters. MATLAB displays an empty string as a pair
of double quotes with nothing between them (""). However, an empty string is still a 1-
by-1 string array. It is not an empty array.

The recommended way to check whether a string is empty is to use the strlength
function.

str = "";
tf = (strlength(str) ~= 0)

NoteDo not use the isempty function to check for an empty string. An empty string has
no characters but is still a 1-by-1 string array.

The strlength function returns the length of each string in a string array. If the string
must be a string scalar, and also not empty, then check for both conditions.

tf = (isStringScalar(str) && strlength(str) ~= 0)

If str could be either a character vector or string scalar, then you still can use
strlength to determine its length. strlength returns 0 if the input argument is an
empty character vector ('').

tf = ((ischar(str) || isStringScalar(str)) && strlength(str) ~= 0)

Update Your Code to Accept Strings