how to know if a char vector contains unwanted characters?

I have this row vector

x=["0","1","2","3","4","5","6","7","8","9","."];

and let us say that there is a vector of char class called y

I want matlab to return true if all the characters in y is from x

and return false if there is any character in y out of x

[Stephen23]

>> x = ['0':'9','.'];
>> all(ismember('123.5',x))
ans = 1
>> all(ismember('OhNo!',x))
ans = 0

But if you are planning to use this concept to check for numbers, note that simply checking for membership of x is not enough to guarantee a valid number syntax:

>> all(ismember('.9.8.7..',x))
ans = 1

[Osama Alkurdi]

but it returns true when y is empty char

[Stephen23]

"but it returns true when x is empty char"

Do you really mean x ? In any case, you can exclude that yourself very easily:

numel(x)>0 && all(ismember(str,x))

[Adam Danz]

"but it returns true when x is empty char"

In your question, x is a string array. So, is x a string array of char array? It matters.

[Osama Alkurdi]

i mean y

[Osama Alkurdi]

sorry

Answer 1

[Adam Danz]

Following the description from your question, here's an anonymous function allCharsGood() with two inputs,

• c is a 1xn char array
• goodList is a 1xn string array

allCharsGood converts the char array c to a string array and then determines whether all elements of c are listed in goodList.

It returns true if all elements of c are in goodList.

It returns false if at least one element of c is not in goodList.

x=["0","1","2","3","4","5","6","7","8","9","."];  % String array
y1 = '3.1415926';  % char array
y2 = '9.56e20';    % char array

allCharsGood = @(c, goodList)all(ismember(string(cellstr(c')'), goodList)); 

allMatch = allCharsGood(y1,x)  % true
allMatch = allCharsGood(y2,x)  % false

Answer 2

[JESUS DAVID ARIZA ROYETH]

y=["5","6","10"];%y example
condition=all(ismember(y,x))

Answer 3

[Joseph Cheng]

check out the function ismember here is snippet of test code

x=["0","1","2","3","4","5","6","7","8","9","."];
y = ["3","3","5","8","1","2"];
checks = ismember(y,x);
disp(x)
disp(y)
disp(checks)
if sum(checks)==numel(y)
    ret = true
else 
    ret = false
end
y = ["10","44","5","8","1","2"];    
checks = ismember(y,x);
if sum(checks)==numel(y)
    ret = true
else 
    ret = false
end

here you can see the two different y character arrays are checked against each other one by one.

[Stephen23]

Complex:

if sum(checks)==numel(y)
    ret = true
else 
    ret = false
end

Simple and efficient:

ret = all(checks)