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Java Collections - Collections.singletonList() Examples

Java Collections Java Java API 


Class:

java.util.Collections

java.lang.Objectjava.lang.Objectjava.util.Collectionsjava.util.CollectionsLogicBig

Method:

public static <T> List<T> singletonList(T o)

Returns an immutable list containing only the specified object.


Examples


package com.logicbig.example.collections;

import java.util.Collections;
import java.util.List;

public class SingletonListExample {

public static void main(String... args) {
List<Integer> list = Collections.singletonList(1);
System.out.println(list);
}
}

Output

[1]




package com.logicbig.example.collections;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class SingletonListExample2 {

public static void main(String... args) {
List<Integer> list = new ArrayList<>();
Collections.addAll(list, 1, null, 4, null, 7, null, null);
System.out.println(list);

list.remove(null);
System.out.println(list);

list.removeAll(Collections.singleton(null));
System.out.println(list);
}
}

Output

[1, null, 4, null, 7, null, null]
[1, 4, null, 7, null, null]
[1, 4, 7]




See Also