add("Volvo"); cars.add("BMW"); cars.add("Ford"); cars.add("Mazda"); System.out.println(cars.contains("BMW")); System.out.println(cars.contains("Toyota")); } } Try it Yourself »Definition and UsageThe contains() method returns true if an item exists in a list and false ...
We have seen a few methods of the ArrayList class before likeadd(),addAll(),remove(),set(),iterate()andclear(). Today we will see thecontains()method. If we need to check if any element is present in the list or not, we can use thecontains()method from the ArrayList class in Ja...
ArrayList.Contains Method發行項 2011/09/08 本文內容 Syntax Version Information See Also Determines whether a specified object is contained in the ArrayList collection.Namespace: System.Collections Assembly: mscorlib (in mscorlib.dll)SyntaxC# 複製 public virtual bool Contains ( Object item ) ...
ArrayList.Contains Method We use optional cookies to improve your experience on our websites, such as through social media connections, and to display personalized advertising based on your online activity. If you reject optional cookies, only cookies necessary to provide you the services will be ...
第二种是借助一个临时ArrayList,向临时List添加数据,调用arrayList.contains(obj)判断是否存在 了解ArrayList的contains原理:调用obj的equals方法进行判断在ArrayList中的位置是否大于零,进而判断是否存在。 publicbooleancontains(Object o) {returnindexOf(o) >= 0; ...
import java.util.Arrays;publicclassArrayListMethod {publicstaticvoidmain(String[] args) { ArrayList<Integer> list =newArrayList<>();//add(E e) add(int index, E e)list.add(1); list.add(2); list.add(0,0);//下标为0的数值设置为0;list.add(0); ...
1.1.4 contains 方法 方法介绍 案例演示 //构建初始容量为10的空列表 List<String> list=new ...
Integer.MAX_VALUE : MAX_ARRAY_SIZE; } //返回ArrayList的大小 public int size() { return size; } // 判断ArrayList是否为空 public boolean isEmpty() { return size == 0; } //判断是否至少包含某一个元素 public boolean contains(Object o) { return indexOf(o) >= 0; } // 返回第一次出现...
booleancontains(Objecto) Returnstrueif this list contains the specified element. voidensureCapacity(int minCapacity) Increases the capacity of thisArrayListinstance, if necessary, to ensure that it can hold at least the number of elements specified by the minimum capacity argument. ...
elements of the ArrayList are stored. * The capacity of the ArrayList is the length of this array buffer... */ transient Object[] elementData; // non-private to simplify nested class access /** * The size of the ArrayList (the number of elements it contains). */ ...