C# check if items in a List<t> exist and increment if it does
<p>I got a CSV file that I read and get 3 values from. The values are: <code>name, date, volume</code>.</p>

<p>I want to do the following, read the file and write it to a <code>List&lt;T&gt;</code> but with a little change. For each item in the CSV file I want to check if the <code>List&lt;T&gt;</code> already contains a line with that <code>name</code> and <code>date</code>. If it does I want the <code>volume</code> in the list increased with +1 if it does not it has to add the line from the csv file to the <code>List&lt;T&gt;</code> with <code>volume = 1</code></p>

<p>So basically i want something like this.</p>

<pre><code> List&lt;T&gt; CsvList = new List&lt;T&gt;();
 foreach (var item in CSV)
 {
     object o = new object(item.name, item.date, item.volume)
     if(CsvList.name.contains(o.name) &amp;&amp; CsvList.date.contains(o.date){
     //Increase the volume of the item in the CsvList where name == o.name and date == o.date;
     }
 }
</code></pre>

<p>Is this possible to achieve in only a C# application. I can write it to a database and check in that database if those values exist, but I don't want to do this with a database.</p>