Please what is wrong with this code?

Write a function called valid_date that takes three positive integer scalar inputs year, month, day. If these three represent a valid date, return a logical true, otherwise false. The name of the output argument is valid. If any of the inputs is not a positive integer scalar, return false as well. Note that every year that is exactly divisible by 4 is a leap year, except for years that are exactly divisible by 100. However, years that are exactly divisible by 400 are also leap years. For example, the year 1900 was not leap year, but the year 2000 was. valid = valid_date(2018,4,1) valid = valid_date(2018,4,31)

[Geoff Hayes]

Ajay - rather than attaching a screen shot of your code, please attach the code itself. Also, please discuss what you thin is wrong with the code. Is there an error? If so, please copy and paste the full error message to this question. Do you get an incorrect answer for some inputs? If so, please copy and paste the inputs that you are using with the observed answer and the expected answer.

[Ajay Raineni]

 Thank you for your reply
it is showing error for
Various inputs
Non-scalar
The last day of every month
Random non-leap years
Random dates

[Geoff Hayes]

And can you attach the code instead of a screen shot? Also, please include the inputs that you are using (i.e. the test cases).

[Ajay Raineni]

function valid = valid_date (year, month, day); 
%Check if the input has 3 elements: 
if nargin < 3; 
    error('The date must have 3 elements') 
else 
    nargin==3; 
    validN=true; 
end 
%Check if the 3 elements are integer, scalars and positives: 
%Also for month between 0 and 12. 
%also fot days between 0 and 31. 
if isscalar(year) && (not(mod(year,1))) == true && year>0 
    validY = true; 
else 
    error('Year has to be integer, scalar and positive') 
end 
if isscalar(month) && (not(mod(month,1))) == true && month > 0 && month <= 12 
    validM = true; 
else 
    error('Month has to be integer, scalar, positive and 0<m<=12') 
end 
if isscalar(day) && (not(mod(day,1))) == true && day > 0 && day <= 31 
    validD = true; 
else 
    error('Day has to be integer, scalar, positive and 0<d<=31') 
end 
if (not(mod(year,4)) == true) && (not(mod(year,400)) == true) 
    if month == 1  3  5  7  8  10  12; 
        day <= 31; 
    elseif month == 2; 
        day <= 29; 
    elseif month == 3  4  6  9  11; 
        day <= 30; 
    end 
else 
    if month == 1  3  5  7  8  10  12; 
        day <= 31; 
    elseif month == 2; 
        day <= 28; 
    elseif month == 3  4  6  9  11; 
        day <= 30; 
    end 
end

if validN == true && validY == true && validM == true && validD == true 
    valid = true; 
else 
    valid = false; 
end

[Ajay Raineni]

inputs valid =valid_date(2018,4,1) valid = valid_date(2018,4,31) valid= valid_date(2025,6,-8)

[Geoff Hayes]

Ajay - don't lines like

if month == 1  3  5  7  8  10  12; 

cause an error for you? You probably want to replace with something similar to

if ismember(month, [1  3  5  7  8  10  12])

I strongly suggest that you use the MATLAB debugger to step through the code while the function is running. As you step through each line, ask yourself if what you are trying to do makes sense and that the answer you get is expected.