MapEntries

MapEntries are a fundamental concept in programming, particularly within data structures that associate keys with values. They represent a single mapping from a key to its corresponding value within a map or dictionary-like structure. Think of it as a single item on a list where each item has two parts: a label (the key) and something associated with that label (the value).

In most programming languages that support maps, a MapEntry typically consists of two distinct components: a key and a value. The key is used to uniquely identify and retrieve the associated value. Keys must generally be immutable and comparable to ensure efficient lookup operations. Values, on the other hand, can be of any data type and do not have the same uniqueness or immutability constraints as keys.

When iterating over a map, you are often working with its MapEntries. This allows you to access both the key and the value of each element within the map. For example, you might loop through a map to print all key-value pairs, or to perform an operation on values based on their keys. The concept of MapEntries is crucial for understanding how to manipulate and utilize key-value stores effectively in various programming contexts.