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);
}