java数组常用方法

以下总结了java数组常用的10个方法!

package com.dxc.collection;

import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

/**
* Created by duanxiangchao on 2015/9/9.
*/
public class ArrayDemo {

public static void main(String[] str){

// 1. 数组的声明、初始化
//定义时指定数组的大小（推荐）
String [] aArray = new String[5];
//定义时直接初始化
String [] bArray = {"a","b","c","e","f"};
String [] cArray = new String[]{"a","b","c","e","f"};

// 2. 使用Arrays.toString(Collection)方法可以数组转变为String
int [] intArray = new int[]{1,2,3,4,5};
String intArrayStr = Arrays.toString(intArray);
System.out.println(intArray.toString());
System.out.println(intArrayStr);

// 3. 判断数组是否包含某个值
boolean contain = Arrays.asList(bArray).contains("a");
System.out.println(contain);

// 4. 用指定的字符串链接数组
String join = StringUtils.join(new String[]{"a", "b", "c", "d", "e"}, ";");
System.out.println(join); //结果 a;b;c;e;f

// 5. 合并两个数组
int [] intArray1 = {1,2,3,4,5};
int [] intArray2 = {6,7,8,9,10};
//Apache commons lang 库
int [] combinedArray = ArrayUtils.addAll(intArray1, intArray2);
System.out.println(combinedArray);

// 6. 数组的反转
int [] arr = {1, 2, 3, 4, 5};
ArrayUtils.reverse(arr);
System.out.println(Arrays.toString(arr));

// 7. 移除元素，会创建新的数组
int [] moveArray = new int[]{1,2,3,4,5,6,7,8,9,10};
int [] removeArray = ArrayUtils.remove(moveArray, 5); //参数为 数组和索引
System.out.println(Arrays.toString(removeArray));

// 8. 根据数组创建ArrayList
String [] array = {"a","b","c","e","f"};
ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(array));
System.out.println(arrayList);

// 9. 将ArrayList转换为数组
Object [] objArray = arrayList.toArray();
System.out.println("ArrayList转数组：" + Arrays.toString(objArray));

// 10. 将数组转化为Set
Set<String> set = new HashSet<String>(Arrays.asList(bArray ));
System.out.println("数组转化Set: " + set);

}

}