Java AbstractList get() 方法及示例

get() 方法属于 java.util.AbstractList 类，用于返回列表中指定位置的元素。

语法：

public abstract E get(int index)

参数： 此方法以元素的索引为参数，该元素将被返回。

返回值： 此方法返回列表中指定位置的元素。

异常： 如果索引超出范围 (index = size())，则此方法将引发 IndexOutOfBoundsException 。

下面是说明get()方法的示例。

示例1：

// Java program to demonstrate
            // get() method
            // for Integer value

            import java.util.*;

            public class GFG1 {
                public static void main(String[] argv) throws Exception {

                    try {

                        // Creating object of AbstractList<Integer>
                        AbstractList<Integer> arrlist1 = new ArrayList<Integer>();

                        // Populating arrlist1
                        arrlist1.add(10);
                        arrlist1.add(20);
                        arrlist1.add(30);
                        arrlist1.add(40);
                        arrlist1.add(50);

                        // print arrlist1
                        System.out.println("ArrayListlist : " + arrlist1);

                        // getting the value at the index 3 using get() method
                        int value = arrlist1.get(3);

                        // print the value
                        System.out.println("Element at index 3 : " + value);
                    }

                    catch (IndexOutOfBoundsException e) {
                        System.out.println("Exception thrown : " + e);
                    }
                }
            }

ArrayListlist : [10, 20, 30, 40, 50]
Element at index 3 : 40

示例2：

// Java program to demonstrate
            // get() method
            // for IndexOutOfBoundsException

            import java.util.*;

            public class GFG1 {
                public static void main(String[] argv) throws Exception {
                    try {

                        // Creating object of AbstractList<Integer>
                        AbstractList<Integer> arrlist1 = new ArrayList<Integer>();

                        // Populating arrlist1
                        arrlist1.add(10);
                        arrlist1.add(20);
                        arrlist1.add(30);
                        arrlist1.add(40);
                        arrlist1.add(50);

                        // print arrlist1
                        System.out.println("ArrayListlist : " + arrlist1);

                        // getting the value at the index 7 using get() method
                        System.out.println("\nTrying to get " + "the element from out" + " of range index ");
                        int value = arrlist1.get(7);

                        // print the value
                        System.out.println("Element at index 7 : " + value);
                    }

                    catch (IndexOutOfBoundsException e) {
                        System.out.println("Exception thrown : " + e);
                    }
                }
            }

ArrayListlist : [10, 20, 30, 40, 50]

Trying to get the element from out of range index 
Exception thrown : java.lang.IndexOutOfBoundsException: Index: 7, Size: 5