Return specific value in MATLAB -

i need write function in matlab that, given birth dates of 2 people in form ( y1,m1,d1,y2,m2,d2 ) (year, month, day) compare them , return 1 if first person older, -1 if first person younger , 0 if have same age. have done following:

function classify( y1,m1,d1,y2,m2,d2 ) if y1 > y2     return -1; elseif y1 < y2     return 1; elseif y1 == y2     if m1 > m2         return -1;     elseif m1 < m2         return 1;     elseif m1 == m2         if d1 > d2             return -1;         elseif d1 < d2             return 1;         elseif d1 == d2             return 0;         end     end end end 

but gives error. how return value in matlab without having declare variable? need return 1,0,-1 depending on result, , seems return 1; not work well.

to have function return value, need declare corresponding variables in function definition line. return function exits function prematurely, not return values itself.

function output = functionname()     %# assign output     output = 1; end 

similarly how can input multiple values, can have return multiple values

function [add, mult] = addandmultiply(a,b)      add = a+b;     mult = a*b;  end 

call as

[u,v] = addandmultiply(1,2); 

now, specific problem compare 2 dates: recommend using datenum:

function firstisolder = classify( y1,m1,d1,y2,m2,d2 )      firstdate  = datenum(y1, m1, d1);     seconddate = datenum(y2, m2, d2);      %# if first older, sign +1, if both equal, sign 0     firstisolder = sign(seconddate - firstdate);