Thread: How can I verify if a date is correct?

How can I verify if a date is correct?

example: 31 02 1999 is not correct, Febrery has only 28 or 29 days.

I would like apreciate some help, i've tryed but i can't do it

this is no function in the standard that does so, so you need to tell us what OS/compiler you use.

i use dev c++ with win xp. i've tried the if function but i can't get it right

I guess you need to write a function that validates the date, examples of things to check:
day <= 31 when month == 1
day <= 29 when month == 2
first figure out all of the conditions.
write an if/elseif/else (or a switch maybe?) construct that validates the date depending on the above conditions, if you still can't get it to work, show us your code, then we will help.

Code:

int daysinmonth(int month,int year){
	int days[]={31,0,31,30,31,30,31,31,30,31,30,31};
	days[1]=((year%4==0 && year%100 !=0) || year%400 ==0)?29:28;
	return days[month-1];
}

int validatedate(int day,int month,int year){
           if(day>= 1 && day <=daysinmonth(month,year))
                         return 1;
           return 0;
}

tks. now i need implant that in something like that:

the program should ask the date until a correct one is inputed. should i do it with a

do
while
???
sorry but i need to do a scholl work and i'm kind of lost

Simple way to force the user to enter a correct date would be

Code:

do
{
  printf("Enter date: ");
  fgets(datebuffer, sizeof(datebuffer), stdin);
}while ( checkdate(datebuffer) );

Where checkdate() is the code above. It would return 0 or 1 depending if its false or true respectivally. You can modify the loop to get the information in the manner you want but the basic idea would stay the same.

i've done like this:

Code:

int diaprov=0,mesprov=0,anoprov=0;


int verificardata()
{
  int datacorrecta=0;
  int diasmeses[]={31,28,31,30,31,30,31,31,30,31,30,31};
  
  
  if (anoprov%4==0) {
  diasmeses[1]=29;
  }
      if (mesprov<1 || mesprov>12) {
      datacorrecta=0;}
      else
          { if (mesprov>=1 && mesprov<=12) {
                if (diaprov>diasmeses[mesprov-1]) { 
                datacorrecta=0;}
                else 
                     {if (diaprov<=diasmeses[mesprov-1] && diaprov>=1) {
                     datacorrecta=1;}
                          }
      return datacorrecta;
    
  }
  }
  }

int main()

{


printf("\n\nData de nascimento (dia mes ano): ");
 do {scanf(" %i  %i %i", &diaprov, &mesprov, &anoprov);}
 while (verificardata()!=1);
 
  contacto[i].dian=diaprov; 
  contacto[i].mesn=mesprov;
  contacto[i].anon=anoprov;

}

COULD YOU TELL ME WHAT IS WRONG. SORRY BOUT THE LANGUAGE BUT I'M PORTUGUESE