Java数组常用方法

数组基础：http://www.cnblogs.com/mengdd/archive/2013/01/04/2844264.html

import java.util.Arrays;

1):创建数组

 String[] a = new String[5]; 
 String[] b = {"a","b","c", "d", "e"}; 
 String[] c = new String[]{"a","b","c","d","e"};

2):输出数组

 import java.util.*;
 class js
 {
     public static void main(String[] args)
     {
         int[] a = { 1, 2, 3, 4, 5 };
         String b = Arrays.toString(a);

         // print directly will print reference value
         System.out.println(a);
         // [I@7150bd4d

         System.out.println(b);
         // [1, 2, 3, 4, 5]
     }
 }

3):从一个数组创建数组列表

 String[] a = { "a", "b", "c", "d", "e" };
 ArrayList<String> List = new ArrayList<String>(Arrays.asList(a));
 System.out.println(List);
 // [a, b, c, d, e]

4):检查一个数组是否包含某个值

 String[] stringArray = { "a", "b", "c", "d", "e" };
 boolean b = Arrays.asList(stringArray).contains("a");
 System.out.println(b);
 // true

5):连接两个数组

int[] a = { 1, 2, 3, 4, 5 }; int[] b = { 6, 7, 8, 9, 10 }; int[] c = ArrayUtils.addAll(a,b);

6):声明一个内联数组

method(new String[]{"a", "b", "c", "d", "e"});

7):把提供的一个数组放入字符串

String j = StringUtils.join(new String[] { "a", "b", "c" }, ", "); System.out.println(j); // a, b, c

8):将一个数组列表转化为数组

 String[] a = { "a", "b", "c", "d", "e" };
 ArrayList<String> aList = new ArrayList<String>(Arrays.asList(a));
 String[] b = new String[aList.size()];
 aList.toArray(b);
 for (String s : b)
     System.out.println(s);

9):将一个数组转化为集(set)

Set<String> set = new HashSet<String>(Arrays.asList(stringArray)); System.out.println(set); //[d, e, b, c, a]

10):逆向一个数组

 int[] intArray = { 1, 2, 3, 4, 5 };
 ArrayUtils.reverse(intArray);
 System.out.println(Arrays.toString(intArray));
 //[5, 4, 3, 2, 1]

11):移除数组中的元素

 int[] intArray = { 1, 2, 3, 4, 5 };
 int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array
 System.out.println(Arrays.toString(removed));

12):将整数转换为字节数组

 byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();
 for (byte t : bytes) {
    System.out.format("0x%x ", t);
 }