Arrays工具类十大常用方法

原文链接: Top 10 Methods for Java Arrays

以下是由 stackoverflow 网站 投票决出的Java数组最常用的十个方法,
0. 声明数组

String[] aArray = new String[5];

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

String[] cArray = new String[]{"a","b","c","d","e"};
1. 打印数组

int[] intArray = { 1, 2, 3, 4, 5 };

String intArrayString = Arrays.toString(intArray);

// 直接打印,则会打印出引用对象的Hash值

// [I@7150bd4d

System.out.println(intArray);

// [1, 2, 3, 4, 5]

System.out.println(intArrayString);
2. 根据数组创建ArrayList

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

ArrayList arrayList = new ArrayList(Arrays.asList(stringArray));

// [a, b, c, d, e]

System.out.println(arrayList);
3. 检查数组是否包含某个值

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

boolean b = Arrays.asList(stringArray).contains("a");

// true

System.out.println(b);
4. 合并连接两个数组

int[] intArray = { 1, 2, 3, 4, 5 };

int[] intArray2 = { 6, 7, 8, 9, 10 };

// Apache Commons Lang 库

int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);
5. 声明内联数组
method(new String[]{"a", "b", "c", "d", "e"});
6. 用给定的字符串连结(join)数组

// containing the provided list of elements

// Apache common lang

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

// a, b, c

System.out.println(j);
7. 将ArrayList转换为数组

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

ArrayList arrayList = new ArrayList(Arrays.asList(stringArray));

String[] stringArr = new String[arrayList.size()];

arrayList.toArray(stringArr);

for (String s : stringArr)

System.out.println(s);

8. 将数组转换为Set

Set set = new HashSet(Arrays.asList(stringArray));

//[d, e, b, c, a]

System.out.println(set);
9. 数组元素反转

int[] intArray = { 1, 2, 3, 4, 5 };

ArrayUtils.reverse(intArray);

//[5, 4, 3, 2, 1]

System.out.println(Arrays.toString(intArray));
10. 移除元素

int[] intArray = { 1, 2, 3, 4, 5 };

int[] removed = ArrayUtils.removeElement(intArray, 3);//创建新的数组

System.out.println(Arrays.toString(removed));
更多——转换int值为字节数组

byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();

for (byte t : bytes) {

System.out.format("0x%x ", t);

}

来自:https://blog.csdn.net/renfufei/article/details/16829457