在Matlab中获得两个输出，而不是一个

Question

这里的问题是在不使用本机Matlab日期函数的情况下查找所提供的日期是否有效。我希望有人能在这里指出我的错误。我也得到了"；在对CCD_ 2"的调用期间未分配的输出自变量CCD_；当我提交Matlab学习工具时出错。

function valid = valid_date(year,month,day)
if nargin~=3
valid = false;
elseif ~isscalar(year)||year<1||year~=fix(year)
valid = false;
return
elseif ~isscalar(month)||month<1||month~=fix(month)
valid = false;
return
elseif ~isscalar(day)||day<1||day~=fix(day)
valid = false;
return
elseif month>12 || day > 31
valid = false;
end
if ((mod(year,4)==0 && mod(year,100)~=0) || mod(year,400)==0)
leapdata=1;
else
leapdata=0;
end
%the below if statements are used to define the months. Some months have 
%31 days and others have 30 days, while February has only 28 days and 29 on
%leap years. this is checked in the below code.
% I feel the below code is where the error is.
if ismember (month, [1 3 5 7 8 10 12])
ismember (day, (1:31))
return
elseif ismember( month, [4 6 9 11])
ismember (day, (1:30))
return
end

if month == 2
if leapdata==1
ismember (day, (1:29))
return
elseif leapdata==0
ismember (day, (1:28))
return
else
valid = false;
end 
end

Answer 1

在Matlab函数结束时返回时，变量valid的值将作为输出发送。在四个注释下面的行中，您需要在if语句内部将变量赋值为true或false。例如：

if ismember(month, [1 3 5 7 8 10 12])
valid = ismember(day, (1:31))
return
elseif ismember(month, [4 6 9 11])
valid = ismember(day, (1:30))
return
end

if month == 2
if leapdata == 1
valid = ismember(day, (1:29))
return
elseif leapdata == 0
valid = ismember(day, (1:28))
return
else
valid = false;
end 
end