Compare a string against list of other strings

Hello,

I would like to understand how to compare a user-inputted string against a list of other strings. I have some extremely verbose code that does work but I am convinced there must be a more elegant solution.

I paste example code below. I am trying to compare a "data rate" against some "permissible rates". Can anyone advise? Thank you.

clear; clc;
data_rate = '288'; % user input
permissible_rates = {'128';'256';'512'}; % validate input against this
check_rate = NaN(size(permissible_rates)); % set up empty array
% Go through the permissible rates, and see if the data rate string is the
% same of any of the permissible rates. If yes, output is 1. If no, output
% is 0
for i=1:length(permissible_rates)
    check_rate(i)=strcmp(data_rate,permissible_rates{i});
end
% if there are no 1s in the array, the user input is invalid
if ismember(1,check_rate) ~= 1
    error('You didn''t choose a correct data rate');
end
% otherwise continue
disp('You choose a correct data rate, congratulations')

[KSSV]

Are you sure they are strings? Why they are strings? Happily you can have them as numbers right?

Answer 1

[KSSV]

data_rate = '288'; % user input
permissible_rates = {'128';'256';'512'}; % validate input against this
idx = contains(permissible_rates,data_rate)

idx = 3×1 logical array
   0
   0
   0

[rkoz575]

Very elegant, with this "contains" function you collapsed 4 of my lines into 1 and removed the need for the loop. Thanks very much for the response.

[Stephen23]

Contains is not the same as your code, compare this answer:

data_rate = '288'; % user input
permissible_rates = {'1228888';'256';'512'};
idx = contains(permissible_rates,data_rate)

idx = 3×1 logical array
   1
   0
   0

vs your code:

idy = NaN(size(permissible_rates)); % set up empty array
for i=1:length(permissible_rates)
    idy(i) = strcmp(data_rate,permissible_rates{i});
end
display(idy)

idy = 3×1

0 0 0

vs STRCMP (the correct answer):

idz = strcmp(data_rate,permissible_rates)

idz = 3×1 logical array
   0
   0
   0

[Steven Lord]

I would use matches, startsWith, or endsWith instead of contains to handle the case where data_rate is part of the text against which you're comparing but not the whole piece of text.

data_rate = '288';
someRates = {'2889','1288', '72883', '288'};
contains(someRates, data_rate) % 288 appears in all four of the someRates

ans = 1×4 logical array
   1   1   1   1

matches(someRates, data_rate) % but only the last is exactly 288

ans = 1×4 logical array
   0   0   0   1

startsWith(someRates, data_rate) % the first starts with 288 (followed by 9)

ans = 1×4 logical array
   1   0   0   1

endsWith(someRates, data_rate) % the second ends with 288 (preceeded by 1)

ans = 1×4 logical array
   0   1   0   1

[rkoz575]

Thank you Steven for the comprehensive answer. I should have realised that contains would fail in the case you mention (where 288 is somewhere in the text). "matches" is a better function to use!

If you submit this as an answer I will accept it.

[ajay kumar]

data_rate = '288';
someRates = {'2889','1288', '72883', '288'};
find(matches(someRates,data_rate))

ans = 4

It will give right index with idx