直接拿来用!超实用的Java数组技巧攻略

本文分享了关于Java数组最顶级的11大方法,帮助你解决工作流程问题,无论是运用在团队环境或是在私人项目中,你都可以直接拿来用!

0. 声明一个数组(Declare an array)

123String[] aArray = new String[5]; String[] bArray = {"a","b","c","d", "e"};String[] cArray = new String[]{"a","b","c","d","e"};

1. 在Java中输出一个数组(Print an array in Java)

123456789int[] intArray = { 1, 2, 3, 4, 5 };String intArrayString = Arrays.toString(intArray);// print directly will print reference valueSystem.out.println(intArray);// [I@7150bd4d System.out.println(intArrayString);// [1, 2, 3, 4, 5]

2. 从数组中创建数组列表(Create an ArrayList from an array)

1234String[] stringArray = {"a", "b","c", "d","e" }; ArrayList<String> arrayList =new ArrayList<String>(Arrays.asList(stringArray));System.out.println(arrayList);// [a, b, c, d, e]

3. 检查数组中是否包含特定值(Check if an array contains a certain value)

1234String[] stringArray = {"a", "b","c", "d","e" }; boolean b = Arrays.asList(stringArray).contains("a");System.out.println(b);// true

4. 连接两个数组(Concatenate two arrays)

1234int[] intArray = { 1, 2, 3, 4, 5 };int[] intArray2 = { 6, 7, 8, 9, 10 };// Apache Commons Lang libraryint[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);

5. 声明一个数组内链(Declare an array inline)

1method(newString[]{"a","b", "c","d", "e"});

6. 将数组元素加入到一个独立的字符串中(Joins the elements of the provided array into a single String)

12345// containing the provided list of elements// Apache common langString j = StringUtils.join(newString[] { "a","b", "c"}, ", ");System.out.println(j);// a, b, c

7. 将数组列表转换成一个数组 (Covnert an ArrayList to an array)

123456String[] 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);

8. 将数组转换成一个集合(Convert an array to a set)

123Set<String> set = new HashSet<String>(Arrays.asList(stringArray));System.out.println(set);//[d, e, b, c, a]

9. 反向数组(Reverse an array)

1234int[] intArray = { 1, 2, 3, 4, 5 };ArrayUtils.reverse(intArray);System.out.println(Arrays.toString(intArray));//[5, 4, 3, 2, 1]

10. 删除数组元素(Remove element of an array)

123int[] intArray = { 1, 2, 3, 4, 5 };int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new arraySystem.out.println(Arrays.toString(removed));

One more – convert int to byte array

12345byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();for (byte t : bytes) { System.out.format("0x%x ", t);}

英文出自: Programcreek你会发现,曾经以为很难做到的事情,

直接拿来用!超实用的Java数组技巧攻略

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