Java数组的12个常用方法

时间：2022-08-16 05:12:40

以下是12个关于Java数组最常用的方法，它们是*得票最高的问题。

声明一个数组

String[] aArray = new String[5];

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

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

打印一个数组

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

String intArrayString = Arrays.toString(intArray);

// print directly will print reference value

System.out.println(intArray);

// [I@7150bd4d

System.out.println(intArrayString);

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

根据数组创建ArrayList

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

ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));

System.out.println(arrayList);

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

判断数组内部是否包含某个值

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

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

System.out.println(b);

// true

连接两个数组

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

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

// Apache Commons Lang library

int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);

声明一个内联数组（array inline）

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

根据分隔符拼接数组元素（去掉最后一个分隔符）

// containing the provided list of elements

// Apache common lang

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

System.out.println(j);

// a, b, c

ArrayList转数组

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

ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));

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

arrayList.toArray(stringArr);

for (String s : stringArr)

    System.out.println(s);

Array转Set

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

System.out.println(set);

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

反转数组

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

ArrayUtils.reverse(intArray);

System.out.println(Arrays.toString(intArray));

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

删除数组元素

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

int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array

System.out.println(Arrays.toString(removed));

整形转字节数组

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

for (byte t : bytes) {

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

}

译文链接：http://www.programcreek.com/2013/09/top-10-methods-for-java-arrays/

相关文章