How to find the Max or the Highest value in (List) No LINQ

Abdalla Omran

In this Method returns the TheQFromDB an Instance from the input list where the property SecondsDiff is the highest and in each item in input has a SecondDiff value but one is the highest . how could i find that without using LINQ ? and how could i check all the items . Look at the Code please

public static TheQFromDB CalculateMaxVal (List input)

{

double maxValue = double.MinValue;

foreach (var item in input)

{

if (item.SecondsDiff > maxValue)

{

maxValue = item.SecondsDiff;

}

Console.WriteLine(maxValue);

return null;

}

5 Replies

Know the answer? Post it — somebody with the same question will find it here.

Michael Extwooh7y ago
Accepted answer
1. public static TheQFromDB CalculateMaxVal (List input)
2. {
3. if (input == null || input.Count < 1)
4. return null;
6. int maxIndex = input.Count - 1;
8. for (int currIndex = input.Count - 2; currIndex >= 0; currIndex--)
9. {
10. if (input[maxIndex].SecondsDiff < input[currIndex].SecondsDiff)
11. maxIndex = currIndex;
12. }
14. Console.WriteLine("Max value: " + input[maxIndex].SecondsDiff);
16. return input[maxIndex];
17. }
+2

Michael Extwooh7y ago

Hello, Abdalla.

Indeed, it does return an object, not the max value.

First off, I look to make sure we aren't in the degenerate situation of having no list or an empty list, and return null in that case.

Then, I look at the list... Take the last object, and assume he has the maximum value. I keep track of a reference to the object in the list as an integer, using the fact that the first item in your list is List[0], followed by List[1], ... List[n-1].

So I walk the list from the back to the front (the currentIndex is decremented) and keep track of the index of the item with the lowest value. Note that I don't have to store that value, I can compare the value in the current object against the value in the object we have currently marked as the max. Where I find a larger value, I revise the index to the current index.

The way it's coded, it'll work properly for the edge case of having a list with just 1 item.

At the end, I print the maxIndex to show how you can get it if you need it, but return the object itself.

Abdalla Omran7y ago

Michael Extwooh

I thank you for your answer but could you explain to me what did you coded . its not clear for me .does give the object back ?

Abdalla Omran7y ago

Laxmidhar Sahoo ,

Thank you for your Code but i want to get the object back and not the maxvalue . the maxvalue is already holding by an Object and that want give back . hope so you have got me what i meant.

Laxmidhar Sahoo7y ago

hi omran you are currect

public static double CalculateMaxVal (List input)
{
double maxValue = double.MinValue;
foreach (var item in input)
{
if (item.SecondsDiff > maxValue)
{
if(item.SecondsDiff != null)
maxValue = item.SecondsDiff;
}
}
Console.WriteLine(maxValue);
return maxValue;
}