If we're using the ParseExact
method for exact date-time's parsing using a specified format, why do we need to provide a IFormatProvider object? what is the point behind it?
For example:
DateTime.ParseExact(dateString, format, provider);
Why do we need the provider
here?
why do we need to provide a IFormatProvider object? what is the point behind it?
It allows for culture-specific options. In particular:
:
or /
in your pattern, which mean culture-specific characters for the time separator or date separator respectivelyAs an example of the last point, consider the same exact string and format, interpreted in the culture of the US or Saudi Arabia:
using System;
using System.Globalization;
class Test
{
static void Main()
{
CultureInfo us = new CultureInfo("en-US");
CultureInfo sa = new CultureInfo("ar-SA");
string text = "1434-09-23T15:16";
string format = "yyyy'-'MM'-'dd'T'HH':'mm";
Console.WriteLine(DateTime.ParseExact(text, format, us));
Console.WriteLine(DateTime.ParseExact(text, format, sa));
}
}
When parsing with the US culture, the Gregorian calendar is used - whereas when parsing with the Saudi Arabian culture, the Um Al Qura calendar is used, where 1434 is the year we're currently in (as I write this answer).