my code is not Undefined variable

outputFolder = fullfile ('DAT');
rootFoder = fullfile  (outputFolder,'leaf_objectCategori');
categories = {'Ilex perado ssp azorica azorica','Geranium sp','Primula vulgaris','Pinus sp'};
i = fullfile("rootFoder","categories");
imds = imageDatastore(fullfile("rootFoder","categories"),'LabelSource', 'foldernames');