Since Java 8, you can use the Map.forEach() method to iterate through a map. An object that maps keys to values. Using foreach in Java 8. A map cannot contain duplicate keys; each key can map to at most one value. undefined. Collection classes that extend Iterable interface can use the forEach() loop to iterate elements. You can use for each loop in Java to iterate through array, Collections(Set, List) or Map. Here is an example on forEach method to iterate over Map. forEach. Java 8 provides a new method forEach() to iterate the elements. Iterate TreeMap entries using forEach. Java 8 - forEach method example with Map. The entrySet method of the TreeMap object returns a Set view of all the entries (i.e. In above example filter, map and sorted are intermediate operations, while forEach is terminal operation. Java 8 – Stream.forEach() We can use streams in Java 8 and above to iterate a map by passing method reference or lambda expression to forEach() method of Stream Interface that performs an action for each element of this stream. Once we get the Set, we can iterate through TreeMap entries using the forEach as given below. The Map interface provides three collection views, which allow a map's contents to be viewed as a set of keys, collection of values, or set of key-value mappings. key-value mappings) stored in the map object. Return value. The basic “for” loop was enhanced in Java 5 and got a name “for each loop”. The forEach method executes the provided callback once for each key of the map which actually … Description. map Optional The map being iterated (myMap in the above Syntax box). Java forEach tutorial shows how to use Java 8 forEach() method. super K, ? Below examples will show how to loop a List and a Map with the new Java 8 API. It’s more readable and reduces a chance to get a bug in your loop. For more specific, the BiConsumer is a functional interface which has a single method void accept(T t, U u); which takes 2 parameters and returns nothing. thisArg Optional Value to use as this when executing callback. It is a default method defined in the Iterable interface. The Java forEach() method is a utility function to iterate over a collection such as (list, set or map) and stream.It is used to perform a given action on each the element of the collection. There are multiple ways to iterate or loop a Map in Java. Here, we will go through several. If you using Java 8 this is the easiest way to loop the Map. This interface takes the place of the Dictionary class, which was a totally abstract class rather than an interface.. It is defined in the Iterable and Stream interface. This is the default method of the Map interface which takes a BiConsumer . forEach is a new method introduced in Java 8 to iterate over collections. 2. 4. We work with consumers and demonstrate forEach() on lists, maps, and set collections. Loop a Map with forEach and lambda expression.