# How to write a function to determine if a date entered is valid

10 visualizzazioni (ultimi 30 giorni)
Elliot Ogbechina il 28 Dic 2019
Commentato: Walter Roberson il 17 Lug 2020
I am to 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. Here is the code i have tried but keeps returning true for all dates, I have editted it a lot and now i just need a fresh eye to point out what i am doing wrong:
NB: I am not to use any built in MatLab function.
function valid = valid_date (year, month, date)
if (nargin==3)
valid=true;
elseif (isinteger(year)) && year>0 && (isscalar(year))
valid=true;
elseif (isinteger(month))&& month>0 && month <=12 && (isscalar(month))
valid=true;
elseif (isinteger(date)) && date > 0 && (isscalar(date))
valid=true;
elseif (month==1||month==3||month==5||month==7||month==8||month==10||month==12)&& date<=31
valid=true;
elseif date <=30
valid=true;
elseif (isinteger(year/4)) && month == 2 && (~(isinteger(year/100))||(isinteger(year/400))) && date <= 29
valid=true;
else
valid = false;
end
##### 9 CommentiMostra 7 commenti meno recentiNascondi 7 commenti meno recenti
Elliot Ogbechina il 31 Dic 2019
so what can i use in place of isinteger
Stephen23 il 31 Dic 2019
Modificato: Stephen23 il 31 Dic 2019
"so what can i use in place of isinteger"
Take a look at this answer you were given six hours ago:
Does it use isinteger? (hint: no)
What does it use? (hint: mod)

Accedi per commentare.

### Risposte (4)

aniket GIRI il 27 Mag 2020
function isvalid = valid_date(y, m, d)
% Check if the inputs are valid
% Check that they are scalars
if ~(isscalar(y) && isscalar(m) && isscalar(d))
isvalid = false;
% Check that inputs are positive
elseif ~all([y, m, d] > 0)
isvalid = false;
% Check that inputs are integers (not the data type)
elseif any(rem([y, m, d], 1))
isvalid = false;
% Check that m and d are below the max possible
elseif (m > 12) || (d > 31)
isvalid = false;
% The inputs could be a valid date, let's see if they actually are
else
% Vector of the number of days for each month
daysInMonth = [31 28 31 30 31 30 31 31 30 31 30 31];
% If leap year, change days in Feb
if isequal(rem(y, 4), 0) && (~isequal(rem(y, 100), 0) || isequal(rem(y, 400), 0))
daysInMonth(2) = 29;
end
maxDay = daysInMonth(m);
if d > maxDay
isvalid = false;
else
isvalid = true;
end
end
end
##### 0 CommentiMostra -2 commenti meno recentiNascondi -2 commenti meno recenti

Accedi per commentare.

MUHAMMAD USMAN BIN AHMED il 1 Giu 2020
function valid = valid_date(year,month,day)
if nargin ~=3
valid=false;
elseif ((~isscalar(year))||(mod(year,1)~=0)||year<=0)
valid=false;
elseif ((~isscalar(month))||(mod(month,1)~=0)||month<=0||month>12)
valid=false;
elseif ((~isscalar(day))||(mod(day,1)~=0)||day<=0)
valid=false;
elseif (any(month==[1,3,5,7,8,10,12]) && day>31)
valid=false;
elseif (any(month==[4,6,9,11]) && day>30)
valid=false;
else
valid=true;
if (rem(year,4)==0 && month==2 && day<=29)
valid=true;
if (rem(year,100)==0)
valid=false;
if rem(year,400)==0
valid=true;
return
end
end
elseif month==2 && day>28
valid=false;
end
end
end
##### 4 CommentiMostra 2 commenti meno recentiNascondi 2 commenti meno recenti
MUHAMMAD USMAN BIN AHMED il 1 Giu 2020
function valid = valid_date_2(year,month,day)
if nargin ~=3
valid=false;
elseif ((~isscalar(year))||(mod(year,1)~=0)||year<=0)
valid=false;
elseif ((~isscalar(month))||(mod(month,1)~=0)||month<=0||month>12)
valid=false;
elseif ((~isscalar(day))||(mod(day,1)~=0)||day<=0)
valid=false;
elseif (any(month==[1,3,5,7,8,10,12]) && day>31)
valid=false;
elseif (any(month==[4,6,9,11]) && day>30)
valid=false;
else
valid=true;
if (rem(year,4)==0 && month==2 && day<=29)
valid=true;
if ((rem(year,100)==0)&& day>28)
valid=false;
if (rem(year,400)==0 && day<=29)
valid=true;
return
end
end
elseif month==2 && day>28
valid=false;
end
MUHAMMAD USMAN BIN AHMED il 1 Giu 2020
is this the correct one?

Accedi per commentare.

Jalaj Gambhir il 31 Dic 2019
Hi,
You can try the following function and see if it works for you:
function valid = valid_date(year, month, date)
if(nargin ~= 3)
valid = false;
elseif (~(mod(year,1)==0) || (year<0) || ~isscalar(year))
valid = false;
elseif (~(mod(month,1)==0) || (month<=0) || (month>12) || ~isscalar(month))
valid = false;
elseif (~(mod(date,1)==0) || (date<=0) || ~isscalar(date))
valid = false;
elseif( (month==1||month==3||month==5||month==7||month==8||month==10||month==12)&& date>31 )
valid = false;
elseif ((month==4||month==6||month==9||month==11) && date>30)
valid = false;
elseif(~leapyear(year) && month==2 && date>28)
valid=false;
elseif(leapyear(year) && month==2 && date>29)
valid=false;
else
valid = true;
end
##### 6 CommentiMostra 4 commenti meno recentiNascondi 4 commenti meno recenti
Anil Muradiya il 1 Giu 2020
Code doesn't work
Walter Roberson il 1 Giu 2020
Anil Muradiya which code are you finding is failing, and what inputs are you finding that it is failing on?

Accedi per commentare.

Sravani Kurma il 17 Lug 2020
Modificato: Sravani Kurma il 17 Lug 2020
function valid=valid_date(year,month,date)
if nargin == 3;
if ~isscalar(year) || year<1|| year~=fix(year)||~isscalar(month) || month<1|| month~=fix(month)||~isscalar(date) || date<1|| date~=fix(date);
valid=false;
else
if ((year/100)~=fix(year/100)&&(year/4)==fix(year/4))||((year/400)==fix(year/400));
%leap yr
valid=mmm(month,date);
else
%non leap year
valid=sss(month,date);
end
end
end
function valid=mmm(month,date)
m30=[4,6,9,11];
m31=[1,3,5,7,8,10,12];
m29=2;
m28=2;
if max((month==m31)')==1
valid=(date>=1)&&date<=31;
elseif max(( month==m30)')==1
valid=(date>=1)&&date<=30;
elseif max((month==m29)')==1
valid=(date>=1)&&date<=29;
else
valid=false;
end
function valid=sss(month,date)
m30=[4,6,9,11];
m31=[1,3,5,7,8,10,12];
m29=2;
m28=2;
if max((month==m31)')==1
valid=(date>=1)&&date<=31;
elseif max(( month==m30)')==1
valid=(date>=1)&&date<=30;
elseif max((month==m28)')==1
valid=(date>=1)&&date<=28;
else
valid=false;
end
##### 1 CommentoMostra -1 commenti meno recentiNascondi -1 commenti meno recenti
Walter Roberson il 17 Lug 2020
What will your code return if nargin is not 3?
if max((month==m31)')==1
Hint: any()

Accedi per commentare.

### Categorie

Scopri di più su Calendar in Help Center e File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by