Common uses of set

Common uses of set include creating a Set, adding elements, deleting elements, determining whether the Set is empty, getting the size of the Set, traversing the Set, finding elements, and set operations. Detailed introduction: 1. Create a Set, Setset=newHashSet(); 2. Add elements, set.add("java"); set.add("python");; 3. Delete elements, set.remove("java"); and so on.

Set is an important collection class in Java. It is mainly used to store unique elements. The Set interface inherits the Collection interface, so it has all the methods in Collection. The following are some common uses of Set:

1. Create a Set

You can use the Set interface to create a new Set object. For example:

Setset=newHashSet();

2. Add elements

You can use the add() method to add elements to the Set. For example:

set.add("java");
set.add("python");

3. Delete elements

You can use the remove() method to delete elements from Set. For example:

set.remove("java");

4. Determine whether the Set is empty

You can use the isEmpty() method to determine whether the Set is empty. For example:

if(set.isEmpty()){
System.out.println("Setisempty");
}

5. Get the size of the Set

You can use the size() method to get the size of the Set. For example:

intsize=set.size();
System.out.println("Setsize:"+size);

6. Traversing the Set

You can use the for-each loop to traverse the elements in the Set. For example:

for(Stringelement:set){
System.out.println(element);
}

7. Find elements

You can use the contains() method to find whether a Set contains an element. For example:

booleancontains=set.contains("python");
System.out.println("Setcontainspython:"+contains);

8. Set operations

You can use set operations (such as union, intersection, difference, etc.) to operate Set. For example:

Setunion=newHashSet(set);
union.addAll(newHashSet("python","javaScript"));
System.out.println("Setunion:"+union);
Setintersection=newHashSet(set);
intersection.retainAll(newHashSet("python","javaScript"));
System.out.println("Setintersection:"+intersection);
Setdifference=newHashSet(set);
difference.removeAll(newHashSet("python","javaScript"));
System.out.println("Setdifference:"+difference);

The above are some common uses of Set. In actual programming, you can flexibly use the Set interface and its methods as needed.

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