Matlab 取得格式化文件名

function s = fileName(folder, k)
    s = num2str(k);
    blankNum = 4 - length(s);
    for i = 1: blankNum
         s = ['0', s];
    end
    s =  [folder, s, '.jpg'];
end

例：

>> f = fileName('C:\FUJun\data\ar\abc\',1)

f =

C:\FUJun\data\ar\abc\0001.jpg