function with text string input and excel file

How can I write a function that takes input of (filename, user_input)... basically the user input would be a text string that will return the values of the corresponding string from the excel sheet.

ex: i want to get info from car model x so my input is 'x' then it returns the following:

car model color HorsePower Mileage

x red 250 20

Answer 1

[Voss]

warning off all
get_car_info('Cars.xlsx','x')

ans = 1×4 table
    carModel     color     HorsePower    Mileage
    ________    _______    __________    _______

     {'x'}      {'red'}       250          20   

get_car_info('Cars.xlsx','y')

ans = 1×4 table
    carModel     color      HorsePower    Mileage
    ________    ________    __________    _______

     {'y'}      {'blue'}       350          27   

get_car_info('Cars.xlsx','z')

ans = 1×4 table
    carModel      color      HorsePower    Mileage
    ________    _________    __________    _______

     {'z'}      {'green'}       200          36   

function out = get_car_info(filename,model)

T = readtable(filename);

% two ways, depending on what the input files might look like:

% 1) this finds where the user-input "model" is located in the first 
%    column of the table, which may or may not be called "carModel":
out = T(strcmp(T{:,1},model),:);

% 2) this finds where the user-input "model" is located in "carModel"
%    column of the table, which may or may not be the first column:
out = T(strcmp(T.carModel,model),:);

end

[ML]

I appreciate it, what would I do if the input was not there? thank you so much!

[Voss]

If one or more inputs are not there, you can use some default values or throw an error; it's up to you to decide what to do.

function out = get_car_info(filename,model)

if ~nargin
    error('not enough input arguments'); % error if no inputs
elseif nargin < 2
    model = 'x'; % default model value if only one input
end

T = readtable(filename);

% two ways, depending on what the input files might look like:
% 1) this finds where the user-input "model" is located in the first 

%    column of the table, which may or may not be called "carModel":
out = T(strcmp(T{:,1},model),:);

% 2) this finds where the user-input "model" is located in "carModel"
%    column of the table, which may or may not be the first column:
out = T(strcmp(T.carModel,model),:);

end

[ML]

Thanks thats reallly helpful. What I meant to aask is what if my input is 'z' but its not there how could I get an error for that?

[Voss]

Including an error check for unmatched specified model:

function out = get_car_info(filename,model)

if ~nargin
    error('not enough input arguments'); % error if no inputs
elseif nargin < 2
    model = 'x'; % default model value if only one input
end

T = readtable(filename);

% two ways, depending on what the input files might look like:

% 1) this finds where the user-input "model" is located in the first 
%    column of the table, which may or may not be called "carModel":
idx = strcmp(T{:,1},model);

% 2) this finds where the user-input "model" is located in "carModel"
%    column of the table, which may or may not be the first column:
idx = strcmp(T.carModel,model);

% in either case, check that there is a valid model match:
if ~any(idx)
    error('model %s does not appear in the table',model);
end

% return the sub-table matching model:
out = T(idx,:);

end