Get Max value from List<myType>

Assuming you have access to LINQ, and Age is an int (you may also try var maxAge - it is more likely to compile):

int maxAge = myTypes.Max(t => t.Age);

If you also need the RandomID (or the whole object), a quick solution is to use MaxBy from MoreLinq

MyType oldest = myTypes.MaxBy(t => t.Age);

thelist.Max(e => e.age);

int max = myList.Max(r => r.Age);

http://msdn.microsoft.com/en-us/library/system.linq.enumerable.max.aspx

Okay, so if you don't have LINQ, you could hard-code it:

public int FindMaxAge(List<MyType> list)
{
if (list.Count == 0)
{
throw new InvalidOperationException("Empty list");
}
int maxAge = int.MinValue;
foreach (MyType type in list)
{
if (type.Age > maxAge)
{
maxAge = type.Age;
}
}
return maxAge;
}

Or you could write a more general version, reusable across lots of list types:

public int FindMaxValue<T>(List<T> list, Converter<T, int> projection)
{
if (list.Count == 0)
{
throw new InvalidOperationException("Empty list");
}
int maxValue = int.MinValue;
foreach (T item in list)
{
int value = projection(item);
if (value > maxValue)
{
maxValue = value;
}
}
return maxValue;
}

You can use this with:

// C# 2
int maxAge = FindMaxValue(list, delegate(MyType x) { return x.Age; });


// C# 3
int maxAge = FindMaxValue(list, x => x.Age);

Or you could use LINQBridge :)

In each case, you can return the if block with a simple call to Math.Max if you want. For example:

foreach (T item in list)
{
maxValue = Math.Max(maxValue, projection(item));
}

How about this way:

List<int> myList = new List<int>(){1, 2, 3, 4}; //or any other type
myList.Sort();
int greatestValue = myList[ myList.Count - 1 ];

You basically let the Sort() method to do the job for you instead of writing your own method. Unless you don't want to sort your collection.

var maxAge = list.Max(x => x.Age);

Easiest way is to use System.Linq as previously described

using System.Linq;


public int GetHighestValue(List<MyTypes> list)
{
return list.Count > 0 ? list.Max(t => t.Age) : 0; //could also return -1
}

This is also possible with a Dictionary

using System.Linq;


public int GetHighestValue(Dictionary<MyTypes, OtherType> obj)
{
return obj.Count > 0 ? obj.Max(t => t.Key.Age) : 0; //could also return -1
}

Simplest is actually just Age.Max(), you don't need any more code.