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直接拿来用!超实用的Java数组技巧攻略

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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。

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)

String[] 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)

int[] 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

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

String[] 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)

int[] 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 )

method(new String[]{"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)

// containing the provided list of elements// Apache common langString j = StringUtils.join(new String[] { "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)

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

Set<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)

int[] 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)

int[] 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

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

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