delete zeros from matrix

How do I delete all the columns that have zeros with a for loop? I tried reducing the number of columns by one in every iteration but matlab shows me "index exceeds matrix dimentions".

p4 = [0 0 31 37 43 47; 0 0 19 13 7 3];

grammes = size(p3,1);

sthles = size(p3,2);

for i = 1 : grammes

for j = 1 : sthles

if iszero(p3(i,j)) == 1

p3(:,j) = [];

sthles = sthles - 1

end

end

end

[Maria K]

Thanks on advance!

Answer 1

[Bruno Luong]

Here is how using FOR-LOOP to delete zero column(s)

A = [0     0    31    37    43    47;
     0     0    19    13     7     3];

[m,n] = size(A);
for j = n:-1:1 % must loop reversing
    deleteflag = true;
    for i = 1 : m
        if A(i,j) ~= 0
            deleteflag =  false;
        end
    end
    if deleteflag % only true if the entire column #j contains 0s
        A(:,j) = [];
    end
end

Answer 2

[madhan ravi]

 p4(:, all(p4 == 0)) = []

[Maria K]

Cool answer but I would like to know how to do it with a for loop..