Let’s learn difference between hashset and treeset in java. Difference between hashset and treeset in java HashSet TreeSet hashset do not maintain any order. sorted according to natural order. If not use compareTo() method. uses equals() method for comparison. uses compareTo() method for ordering two objects. hashset is implemented using HashTable. TreeSet is implemented using…
Read More Difference between hashset and treeset in javaLet’s learn how to sort treeset in descending order in java. How to sort treeset in descending order in java In this post lets sort treeset elements in descending order or decreasing order. For this we are using descendingSet() method. This method returns a reverse order view of the elements contained in this set. import…
Read More How to sort treeset in descending order in javaLet’s learn iterate treemap in java. iterate treemap in java We cannot iterate TreeMap using iterators since TreeMap is not a collection. To iterate use entrySet() method of TreeMap class. entrySet() method returns a Set view of the mappings contained in this map. We can iterate over key-value pair using getKey() method and getValue() method…
Read More iterate treemap in javaLet’s learn java treemap sort by value. Java treemap sort by value TreeMap stores key-value pairs which are in sorted order based on key. To sort a treemap by value we have to build some logic using comparator class. Here’s an example on how to sort a treemap by value. import java.util.Comparator; import java.util.Iterator; import…
Read More Java treemap sort by valueLet’s learn java treemap comparator() method example. Java treemap comparator() method example TreeMap comparator() method returns the comparator used to order the keys in this map, or null if this map uses the natural ordering of its keys. Let’s see example on TreeMap comparator() method for natural ordering. import java.util.Comparator; import java.util.NavigableMap; import java.util.TreeMap; public…
Read More Java treemap comparator() method exampleLet’s learn difference between for and for each loop in java. Difference between for and for each loop in java Here’s the difference between for loop and for-each loop in java. for loop for each loop Here in for loop we can change counter as per our wish. Executes in a sequential manner. Counter will…
Read More Difference between for and for each loop in javaLet’s learn how to sort an array without using sort method in java. How to sort an array without using sort method in java In the below program on how to sort an array without using sort method we are not using Arrays.sort() method to sort given array. Meanwhile we are sorting array elements in…
Read More How to sort an array without using sort method in javaLet’s learn why string is immutable in java. Why string is immutable in java why string is immutable? Strings are immutable in java because String objects are cached in string constant pool. String object once created cannot be changed i.e, when object is assigned to variable we cannot update the reference. If string object is…
Read More Why string is immutable in javaLet’s learn scope and lifetime of variables in java. Scope and lifetime of variables in java I have discussed variables in java in my earlier post. Now let’s learn the scope and lifetime of variables. Local variable scope is within the block where it is declared and lifetime is until control exits the block in…
Read More Scope and lifetime of variables in javaLet’s learn java switch case with multiple values. Java switch case with multiple values Let’s learn to check java switch case on multiple values. Here’s an example on java switch case multiple values. public class SwitchCaseMultipleValues { public static void main(String[] args) { int number = 1; switch(number) { case 1: case 2: System.out.println(“number 1”);…
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