Setbefore retainAll()operation:[1,2,3,4,5] CollectionElementsto be retained:null Tryingtopassnullasa specified element Exceptionthrown:java.lang.NullPointerException 参考:https:// docs.oracle.com/javase/7/docs/api/java/util/Set.html#retainAll(java.util.Collection) 注:本文由VeryToolz翻译自Set ...
首先想到的是contains()但是它的参数只能传Object,还有另一个也就是retainAll()它可以传Collection<?>。 2.代码测试 public class TestRetainAll {public static void main(String[] args) {// 创建一个集合ArrayList<String> one = new ArrayList<>();one.add("a");one.add("b");one.add("c");System...
ArrayList 1: [a, b, c] ; isContains:true ArrayList 1: [a, b] ; isRetainAll:true 1. 2. 3. 4. 3.总结 retainAll 方法: Retains only the elements in this list that are contained in the specified collection. In other words, removes from this list all of its elements that are not ...
addAll(c):添加所有至调用对象的末尾; remove(Object):从调用它的对象中,移除对应单个实例; retainAll():取交集,存入调用它的一方 addAll():将参数方的所有元素都添加到调用方 removeAll():移除调用一方中与参数相同的数据 containAll():检查调用方是否包含参数中的所有数据,真则反悔true,反之为false interator(...
Java的Set集合中的retainAll()方法 我们来看官方文档: booleanretainAll(Collection<?> c) Retains only the elements in this set that are contained in the specified collection (optional operation). In other words, removes from this set all of its elements that are not contained in the ...
java 取交集方法retainAll java 取交集方法retainAll 有两个集合newCoures和oldCourses,判断这两个集合是否包含相同的对象或元素, 可以使用retainAll方法:oldCourses.retainAll(newCoures)。 如果存在相同元素,oldCourses中仅保留相同的元素。 如果不存在相同元素,oldCourse会变为空。
ArrayList retainAll() method in Java ArrayList的retainAll()方法用于移除所有未包含在指定集合中的数组列表元素或保留所有匹配的元素当前 ArrayList 实例,它匹配作为参数传递给方法的 Collection 列表中的所有元素。语法: publicbooleanretainAll(CollectionC)
Java 中的 ArrayList retainAll()方法 原文:https://www . geesforgeks . org/ArrayList-retailnall-method-in-Java/ 数组列表 的retainnal()方法用于移除指定集合中未包含的所有数组列表元素,或者保留当前数组列表实例中所有匹配元素,这些元素匹配作为参数传递给该方法
ISet.RetainAll(ICollection) Method Reference Feedback Definition Namespace: Java.Util Assembly: Mono.Android.dll Retains only the elements in this set that are contained in the specified collection (optional operation). C#复制 [Android.Runtime.Register("retainAll","(Ljava/util/Collection;)Z","Get...
public virtual bool RetainAll (Android.Runtime.JavaList collection); Parametri collection JavaList Restituisce Boolean Commenti Le parti di questa pagina sono modifiche basate sul lavoro creato e condiviso dal progetto Open Source Android e usato in base ai termini descritti nella licenza Creativ...