how I can know if a string is empty or not!?

please help me with a code ! thank you !

Answer 1

[Guillaume]

How about the helpfully named isempty?:

>>isempty('aaa')
ans = 
    0

>>isempty('')
ans = 
    1

Note that because strings are just matrices (of characters), it's the same test you use for matrix emptiness.

[Imen Mani]

Ok ! thank you for your help :)

[Caglar]

Note that isempty() works for chars but not strings.

>>isempty("aaa")
ans=
    0
    
>>isempty("")
ans=
    0
    
    

So if one is not sure if the variable is a char array or string, variable should be compared to "" with strcmp or "==".

[Adam Danz]

For strings or char arrays, you can use,

TF = strlength(s)==0;   % r2016b or later

Demo

strlength('word')   % ans = 4
strlength("word")   % ans = 4
strlength("")       % ans = 0
strlength('')       % ans = 0

If the string is scalar,

isempty(char(s))

Demo

s = "";
isempty(char(s))    % ans = 1

[Stephen23]

"" is not an empty string array, it is a scalar string array (which happens to have zero characters, but the number of characters is totally irrelevant to the size of the string array):

>> isscalar("aaaaaaaaa")
ans=
    1
>> isscalar("")
ans=
    1

If you want to know how many characters are in the elements of a string array, use strlength:

https://www.mathworks.com/help/matlab/ref/strlength.html

Answer 2

[Weird Rando]

You can use the length()

a = '';

stringlen = length(a) % stringlen = 0

[Imen Mani]

Ok ! thank you for your help :)