All MethodsInstance MethodsConcrete Methods 解析ArrayList的构造函数 //默认构造函数,默认容量大小为10ArrayList()//capacity是ArrayList的默认容量大小。每次扩容为原来的1.5倍。ArrayList(intcapacity)//创建一个包含collection的ArrayList,可以将别的ArrayList数组复制进去ArrayList(Collection<?extendsE> collection) ArrayList...
我们可以看一下,ArrayList实现类源码中的第一段注释: Resizable-array implementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array t...
list1.addAll(list2); 3. boolean addAll(int index, Collection c):此方法用于在列表中的指定位置添加一组元素。例如: list1.addAll(2, list2): // Adding all elements of list2 at position index 2 in list1 4. void add(int index, Object o):用于在列表中的特定位置索引处添加一个元素。例如...
@Test(expected = UnsupportedOperationException.class)publicvoidgivenUsingGuavaBuilder_whenUnmodifiableListIsCreated_thenNoLongerModifiable(){ List<String> list =newArrayList<>(Arrays.asList("one","two","three")); ImmutableList<String> unmodifiableList = ImmutableList.<String>builder().addAll(list).build...
Here’s an example of using some of these methods: ArrayList<String>names=newArrayList<String>();names.add("John");names.add("Alice");names.set(0,"Bob");names.remove(1);System.out.println(names);#Output:#[Bob] Java Copy In this example, we first created an ArrayList named ‘names’...
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 J...
ArrayList class provides a method toArray() which directly converts an ArrayList to Array. It can be done in following way. ArrayList类提供了toArray()方法,该方法将ArrayList直接转换为Array。 可以通过以下方式完成。 package com; import java.util.ArrayList; ...
All MethodsInstance MethodsConcrete Methods Modifier and TypeMethod and Description booleanadd(Ee) Appends the specified element to the end of this list. voidadd(int index,Eelement) Inserts the specified element at the specified position in this list. ...
In order to find an element you may useindexOf()orlastIndexOf()methods. They both accept an object and returnintvalue: assertEquals(10, stringsToSearch.indexOf("a")); assertEquals(26, stringsToSearch.lastIndexOf("a"));Copy If you want to find all elements satisfying a predicate, you ...
Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array that is used internally to store the list. (This class is roughly equivalent to Vector, except that ...