MATLAB: Find elements in table without looping (Matlab)

accelerateelementfindfor looptable

As this seems to be a quite common problem, I have spent a while trying to find a suitable answer for my case in other posts. However, most of them are full of maths and I cannot see the solution very clear.
This is my case:
I generated a function that imports data into Matlab in form of a table. The table looks like:
This table has around one million of rows. Basically, I need to extract from this table just the rows where the table1.ID matches 'DHK' and leave the result in another table.
This is the code I have just now:
 cont=0;
 for p=1:length(table1.ID)
            ID=table1.ID(p,1);
            IDstr=ID{1,1};
            if strcmp(IDstr,'DHK')==1
                cont=cont+1;
                var1(cont,1)=table1.var1(p,1);
                var2(cont,1)=table1.var2(p,1);
                var3(cont,1)=table1.var3(p,1);
                var4(cont,1)=table1.var4(p,1);
            end
  end
 table2=table(var1,var2,var3,var4);
This code works but it takes extremely long time as I am dealing with a million of rows and many import files. There migth be a better way or command that automatically finds the information that I need instead of looking for it line by line?. I found this MATLAB link on the documentation but I am not sure how to apply it for what I need: http://uk.mathworks.com/help/matlab/matlab_prog/find-array-elements-that-meet-a-condition.html
I would be very grateful if somebody could help me.

Best Answer

v={'ID'   'var1' 'var2' ;'DHK' 12 14; 'ABC',15 20;'DHK',15 13}
w=cell2table(v(2:end,:),'variablenames',v(1,:))   % Example
out=w(ismember(w.ID,'DHK'),:)
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