How can I use the struct function to struct my data set. And be able to perform a forloop . As show in my code

%% Loading Data
% using the excel data 
[FileName, PathName] = uigetfile('*.xlsx','Select Excel files to analyze:','MultiSelect','off');
[status, sheets] = xlsfinfo([PathName, FileName]);
summary_data = xlsread([PathName, FileName],sheets{1});

Volume = summary_data(:,1); % in mL
Time = summary_data(:,2); % in Seconds 
Power = summary_data(:,3); % in watts;

data = struct('volume',[],'time ',[],'power',[]);
 
 
% for j = 1:length(sheets)-1 ;
%     rawdata = xlsread([PathName, FileName],sheets{j+1}); 
%     data(j).volume = rawdata(:,1);
%     data(j).time = rawdata(:,2);
%     data(j).power= rawdata(:,3);

Answer 1

[Walter Roberson]

%% Loading Data
% using the excel data 
[FileName, PathName] = uigetfile('*.xlsx','Select Excel files to analyze:','MultiSelect','off');
[status, sheets] = xlsfinfo([PathName, FileName]);
summary_data = xlsread([PathName, FileName],sheets{1});
Volume = summary_data(:,1); % in mL
Time = summary_data(:,2); % in Seconds 
Power = summary_data(:,3); % in watts;
numsheets = length(sheets);
data(numsheets-1) = struct('volume',[],'time ',[],'power',[]); 
 
for j = 1:numsheets-1 ;
    rawdata = xlsread([PathName, FileName],sheets{j+1}); 
    data(j).volume = rawdata(:,1);
    data(j).time = rawdata(:,2);
    data(j).power= rawdata(:,3);
end