Dictionary<TKey, TValue> provide fast lookups, based on keys, to get values. With them, we use keys and values of any type, including int and string. Dictionary is used with different elements. We specify its key type and its value type (string, int).
Define a Dictionary
We specify its key type and its value type (string, int).
Add elements to a Dictionary
Here’s how to add elements to a
Read and update existing values
To read a value use the following statement.
To update an existing value simply use the following.
Check if a key exists in a Dictionary
This sees if a given string is present in a Dictionary.
Iterate through a Dictionary
Here we loop over
KeyValuePairs in a
Dictionary. With collections like
Dictionary, we must always know the value types. With each
KeyValuePair, there is a
Key member and
Remove elements from a Dictionary
Here’s how you can remove elements from a
Count elements in a Dictionary
This computes the total number of keys in a
Dictionary. This is simpler than accessing the
Keys property, or looping over the
Dictionary to count it.
Clear all elements from a Dictionary
We can erase all pairs with the
Check if a value exists in a Dictionary
This method lacks the constant-time look up speed of ContainsKey. It instead searches the entire collection.
Get all keys of a Dictionary
Here we use the Keys property. We then look through each key and look up the values.