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 }; 2 int[] b = { 6, 7, 8, 9, 10 }; 3 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" }, ", "); 2 System.out.println(j); 3 // 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)); 2 System.out.println(set); 3 //[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);
}