Simplify code with nested if

I have a matrix C in which every row contains dates and times. In the fourth column months are indicated as Jun, Feb, Mar, etc... I would like to replace such abbreviations with their corresponding numeric values: Jan->1, Feb->2, etc... My first attempt is:

for i=1:size(C,1)
    if C(i,4)=='Jen' C(i,4)==1;
    elseif C(i,4)=='Feb' C(i,4)==2; ... etc
    end
end

Is there any way for simplify this code?

[the cyclist]

What data type is C?

[Gaetano Pavone]

C is a 153435x34 cell

Answer 1

[the cyclist]

% A little pretend data, where I only fill in the 4th column with a few months
C = cell(5,6);
C(:,4) = {'Jan';'Jan';'Dec';'Mar';'Jul'};

% Replace the 4th column with the numeric indices
C(:,4) = num2cell(month(datetime(C(:,4),'Format','MMM')));

[Gaetano Pavone]

C(:,4) actually is like:

C(:,4) = {"Jan";"Jan";"Dec";"Mar";"Jul"};

your code doesn't work for this format

[the cyclist]

Try

month(datetime([C{:,4}],"Format","MMM"))

instead. That creates a string array from the cell array of strings, which is an allowed input to the datetime function.