arraylist实例

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package test;

import java.io.*;
import java.util.Random;
import java.util.Scanner;
import java.util.ArrayList;
import java.util.List;

public class test {

public static void main(String[] args) {
List<String> list=new ArrayList<String>();
System.out.println("长度:"+list.size());

for(int i=0;i<10;i++) {
list.add(GenRandomString(5));
}

list.add("abc");

System.out.println("arraylist中否为空:"+list.isEmpty());
System.out.println("arraylist个元素个数为:"+list.size());
System.out.println("arraylist中是否含有abc:"+list.contains("abc"));
System.out.println("arraylist第一次出现abc的位置:"+list.indexOf("abc"));
System.out.println("arraylist最后一次出现abc的位置:"+list.lastIndexOf("abc"));

Object[] objectArray=list.toArray();
System.out.println("生成的数组为：");
for(Object obj:objectArray) {
System.out.println(obj);
}

System.out.println("列表中第一个元素为:"+list.get(0));
String old=list.set(0, "abc");
System.out.println("第一个元素"+old+"被替换成了abc");
System.out.println("是否插入成功："+list.add("def"));
list.add(0,"ghi");
System.out.println("移出指定元素"+list.remove(0));
System.out.println("元素是否被移出:"+list.remove("abc"));

List<String> list2=new ArrayList<String>();
list2.add(GenRandomString(5));
list2.add(GenRandomString(5));
list.addAll(list2);

System.out.println("新列表为:");
for(String str:list) {
System.out.println(str);
}

list.clear();
System.out.println("移出所有元素后列表的长度为:"+list.size());

}

public static String GenRandomString(int length) {
Random random=new Random();
char[] charArray={};

charArray="abcdefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ".toCharArray();
char[] randomChar=new char[length];
for(int i=0;i<length;i++) {
randomChar[i]=charArray[random.nextInt(61)];
}
return new String(randomChar);
}
}

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