Java Collections - disjoint() Method
The java.util.Collections.disjoint() method returns true if the two specified collections have no elements in common.
Syntax
public static boolean disjoint(Collection<?> c1,
Collection<?> c2)
Here, T is the type of element in the list.
Parameters
c1 |
Specify a collection. |
c2 |
Specify another collection. |
Return Value
Returns true if the two specified collections have no elements in common.
Exception
- Throws NullPointerException, if either collection is null.
- Throws NullPointerException, if one collection contains a null element and null is not an eligible element for the other collection. (optional)
- Throws ClassCastException, if one collection contains an element that is of a type which is ineligible for the other collection. (optional)
Example:
In the example below, the java.util.Collections.disjoint() method is used to check whether given collections are disjoint or not.
import java.util.*;
public class MyClass {
public static void main(String[] args) {
//creating a list objects
List<Integer> list1 = new ArrayList<Integer>();
List<Integer> list2 = new ArrayList<Integer>();
List<Integer> list3 = new ArrayList<Integer>();
//populating list1
list1.add(10);
list1.add(20);
//populating list2
list2.add(20);
list2.add(10);
//populating list3
list3.add(100);
//checking list1 and list2 for disjoint
boolean retval = Collections.disjoint(list1, list2);
System.out.println("list1 and list2 are disjoint? - " + retval);
//checking list1 and list3 for disjoint
retval = Collections.disjoint(list1, list3);
System.out.println("list1 and list3 are disjoint? - " + retval);
}
}
The output of the above code will be:
list1 and list2 are disjoint? - false list1 and list3 are disjoint? - true
❮ Java.util - Collections
