There are two variants of first() in Java.util.TreeMap, both are discussed in this article.
1. firstEntry() : It returns a key-value mapping associated with the least key in this map, or null if the map is empty.
Syntax : public Map.Entry firstEntry() Parameters: NA Return Value: It returns an entry with the least key and null if the map is empty. Exception: NA
Lowest entry is: 1=one
2. firstKey() : It returns the first (lowest) key currently in the map.
Syntax : public K firstKey() Parameters: NA Return Value: It returns the first (lowest) key currently in this map. Exception: NA NoSuchElementException : It is thrown if this map is empty.
Lowest key is: 1
Practical Application : These functions can be used to fetch best ranked person in given list, or can be used to assign winner in game in which person with lowest time to finish a task wins. Latter one is discussed below.
Winner with lowest time is : 1.3=Shambhavi
This article is contributed by Shambhavi Singh . If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
- SortedMap firstKey() method in Java
- Java.util.LinkedList.poll(), pollFirst(), pollLast() with examples in Java
- Java lang.Long.numberOfTrailingZeros() method in Java with Examples
- Java.util.function.DoublePredicate interface in Java with Examples
- Java lang.Long.numberOfLeadingZeros() method in Java with Examples
- Java.util.function.BiPredicate interface in Java with Examples
- Java.util.Collections.disjoint() Method in java with Examples
- Java.lang.Short toString() method in Java with Examples
- Java.util.concurrent.Phaser class in Java with Examples
- Java.util.concurrent.RecursiveTask class in Java with Examples
- Java lang.Long.lowestOneBit() method in Java with Examples
- Java.util.function.LongPredicate interface in Java with Examples
- Java.util.LinkedList.peek() , peekfirst(), peeklast() in Java
- Java lang.Long.byteValue() method in Java with Examples
- Java lang.Long.reverse() method in Java with Examples