I have two DateTime objects: StartDate and EndDate. I want to make sure StartDate is before EndDate. How is this done in C#?
This question is related to
c#
StartDate < EndDate
if (StartDate>=EndDate)
{
throw new InvalidOperationException("Ack! StartDate is not before EndDate!");
}
if(StartDate < EndDate)
{}
DateTime supports normal comparision operators.
I'd like to demonstrate that if you convert to .Date that you don't need to worry about hours/mins/seconds etc:
[Test]
public void ConvertToDateWillHaveTwoDatesEqual()
{
DateTime d1 = new DateTime(2008, 1, 1);
DateTime d2 = new DateTime(2008, 1, 2);
Assert.IsTrue(d1 < d2);
DateTime d3 = new DateTime(2008, 1, 1,7,0,0);
DateTime d4 = new DateTime(2008, 1, 1,10,0,0);
Assert.IsTrue(d3 < d4);
Assert.IsFalse(d3.Date < d4.Date);
}
if (new DateTime(5000) > new DateTime(1000))
{
Console.WriteLine("i win");
}
This is probably too late, but to benefit other people who might stumble upon this, I used an extension method do to this using IComparable like this:
public static class BetweenExtension
{
public static bool IsBetween<T>(this T value, T min, T max) where T : IComparable
{
return (min.CompareTo(value) <= 0) && (value.CompareTo(max) <= 0);
}
}
Using this extension method with IComparable makes this method more generic and makes it usable with a wide variety of data types and not just dates.
You would use it like this:
DateTime start = new DateTime(2015,1,1);
DateTime end = new DateTime(2015,12,31);
DateTime now = new DateTime(2015,8,20);
if(now.IsBetween(start, end))
{
//Your code here
}
You can use the overloaded < or > operators.
For example:
DateTime d1 = new DateTime(2008, 1, 1);
DateTime d2 = new DateTime(2008, 1, 2);
if (d1 < d2) { ...
I had the same requirement, but when using the accepted answer, it did not fulfill all of my unit tests. The issue for me is when you have a new object, with Start and End dates and you have to set the Start date ( at this stage your End date has the minimum date value of 01/01/0001) - this solution did pass all my unit tests:
public DateTime Start
{
get { return _start; }
set
{
if (_end.Equals(DateTime.MinValue))
{
_start = value;
}
else if (value.Date < _end.Date)
{
_start = value;
}
else
{
throw new ArgumentException("Start date must be before the End date.");
}
}
}
public DateTime End
{
get { return _end; }
set
{
if (_start.Equals(DateTime.MinValue))
{
_end = value;
}
else if (value.Date > _start.Date)
{
_end = value;
}
else
{
throw new ArgumentException("End date must be after the Start date.");
}
}
}
It does miss the edge case where both Start and End dates can be 01/01/0001 but I'm not concerned about that.
You can use the overloaded < or > operators.
For example:
DateTime d1 = new DateTime(2008, 1, 1);
DateTime d2 = new DateTime(2008, 1, 2);
if (d1 < d2) { ...
StartDate < EndDate
if (StartDate>=EndDate)
{
throw new InvalidOperationException("Ack! StartDate is not before EndDate!");
}
Check out DateTime.Compare method
You can use the overloaded < or > operators.
For example:
DateTime d1 = new DateTime(2008, 1, 1);
DateTime d2 = new DateTime(2008, 1, 2);
if (d1 < d2) { ...
Check out DateTime.Compare method
if (new DateTime(5000) > new DateTime(1000))
{
Console.WriteLine("i win");
}
if(StartDate < EndDate)
{}
DateTime supports normal comparision operators.
I'd like to demonstrate that if you convert to .Date that you don't need to worry about hours/mins/seconds etc:
[Test]
public void ConvertToDateWillHaveTwoDatesEqual()
{
DateTime d1 = new DateTime(2008, 1, 1);
DateTime d2 = new DateTime(2008, 1, 2);
Assert.IsTrue(d1 < d2);
DateTime d3 = new DateTime(2008, 1, 1,7,0,0);
DateTime d4 = new DateTime(2008, 1, 1,10,0,0);
Assert.IsTrue(d3 < d4);
Assert.IsFalse(d3.Date < d4.Date);
}
I had the same requirement, but when using the accepted answer, it did not fulfill all of my unit tests. The issue for me is when you have a new object, with Start and End dates and you have to set the Start date ( at this stage your End date has the minimum date value of 01/01/0001) - this solution did pass all my unit tests:
public DateTime Start
{
get { return _start; }
set
{
if (_end.Equals(DateTime.MinValue))
{
_start = value;
}
else if (value.Date < _end.Date)
{
_start = value;
}
else
{
throw new ArgumentException("Start date must be before the End date.");
}
}
}
public DateTime End
{
get { return _end; }
set
{
if (_start.Equals(DateTime.MinValue))
{
_end = value;
}
else if (value.Date > _start.Date)
{
_end = value;
}
else
{
throw new ArgumentException("End date must be after the Start date.");
}
}
}
It does miss the edge case where both Start and End dates can be 01/01/0001 but I'm not concerned about that.
if (StartDate>=EndDate)
{
throw new InvalidOperationException("Ack! StartDate is not before EndDate!");
}
if(StartDate < EndDate)
{}
DateTime supports normal comparision operators.
Check out DateTime.Compare method
This is probably too late, but to benefit other people who might stumble upon this, I used an extension method do to this using IComparable like this:
public static class BetweenExtension
{
public static bool IsBetween<T>(this T value, T min, T max) where T : IComparable
{
return (min.CompareTo(value) <= 0) && (value.CompareTo(max) <= 0);
}
}
Using this extension method with IComparable makes this method more generic and makes it usable with a wide variety of data types and not just dates.
You would use it like this:
DateTime start = new DateTime(2015,1,1);
DateTime end = new DateTime(2015,12,31);
DateTime now = new DateTime(2015,8,20);
if(now.IsBetween(start, end))
{
//Your code here
}
if (StartDate>=EndDate)
{
throw new InvalidOperationException("Ack! StartDate is not before EndDate!");
}
Check out DateTime.Compare method
if (new DateTime(5000) > new DateTime(1000))
{
Console.WriteLine("i win");
}
StartDate < EndDate
Source: Stackoverflow.com