Java 8 brought some of the major changes in the Collection Framework, Specifically in Map Interface such as.
computeIfPresent
If a key is present in Map then it needs to be updated with a new value which must be computed via another Function.
computeIfAbsent
A lot of times if a key is not present in Map then it needs to be added to the Map and its value must be computed via another Function.
getOrDefault
Sometimes situations arise where a key needs to be updated from a value from the map, and if not present then a default value must be assigned.
compute
Most of the time, a value from a map needs to be updated, the traditional way is to get the value from the map if the value is present then update the value and put it back on to map.
forEach
Looping or Iteration over the Collections and Map is one of the important aspects of Collections. Prior to Java 8, List and Set could be looped via enhanced for loop and Map could be iterated using Entry Set.
Replace and ReplaceAll
Certain times the single entire value or the entire value of the map needs to be updated, in the case of a single update, the traditional way is to get the value based on the key or for the entire value, iterate the whole Map over the entry set and update each entry.
let's understand each of them one by one.
