List和数组的相互转化

一、数组转化为list：Arrays.aslist(arr);

public static void main(String[] args) {
    String[] arr={"apple","pear"};
    List<String> list=Arrays.asList(arr);
    System.out.println(list.size()); //===>2
}

 

二、list转化为数组 list.toArray();

package com.cmc.util;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

public class listUtil {

    public static void main(String[] args) {
        List<String> list = new ArrayList<String>();  
        list.add("str1");  
        list.add("str2");
        int size=list.size();
        String[] arr2= list.toArray(new String[size]);  //*** 设置数组的大小
        for (int i = 0; i < arr2.length; i++) {
            System.out.println("==arr2==:"+arr2[i]);
        }
    }
}