How to lookup / check a dictionary value by key

Question

I am trying to confirm whether a specific dictionary key contains a value

e.g.

does dict01 contain the phrase "testing" in the "tester" key

At the moment I am having to iterate through the dictionary using KeyPair, which I don't want to have to do as it wasting performance

Answer 1

You can use ContainsKey and string.Contains:

var key = "tester";
var val = "testing";
if(myDictionary.ContainsKey(key) && myDictionary[key].Contains(val)) 
{
    // "tester" key exists and contains "testing" value
}

You can also use TryGetValue:

var key = "tester";
var val = "testing";
var dicVal = string.Empty;
if(myDictionary.TryGetValue(key, out dicVal) && dicVal.contains(val)) 
{
    // "tester" key exists and contains "testing" value
}

Answer 2

You can use the following method if you don't want to iterate through the dictionary twice

string value;
var result = dict01.TryGetValue("tester", out value) && value.Contains("testing");