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Java技巧:Java数组技巧攻略

作者:课课家教育     来源: http://www.kokojia.com点击数:837发布时间: 2016-02-29 20:03:27

标签: java系统架构师java数组初始化java工程师待遇

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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!

Java技巧:Java数组技巧攻略_java系统架构师_java数组初始化_课课家  

       0. 声明一个数组(Declare an array)

  [js] view plaincopyString[] 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)

  [js] view plaincopyint[] 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]

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

  [js] view plaincopyString[] stringArray = { "a", "b", "c", "d", "e" };

  ArrayList arrayList = new ArrayList(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)

  [js] view plaincopyString[] 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)

  [js] view plaincopyint[] intArray = { 1, 2, 3, 4, 5 };

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

  // Apache Commons Lang library

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

  5. 声明一个数组内链(Declare an array inline )

  [js] view plaincopymethod(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)

  [js] view plaincopy// 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

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

  [js] view plaincopyString[] 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. 将数组转换成一个集合(Convert an array to a set)

  [js] view plaincopySet set = new HashSet(Arrays.asList(stringArray));

  System.out.println(set);

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

  9. 反向数组(Reverse an array)

  [js] view plaincopyint[] 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)

  [js] view plaincopyint[] intArray = { 1, 2, 3, 4, 5 };

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

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

  One more – convert int to byte array

  [js] view plaincopybyte[] bytes = ByteBuffer.allocate(4).putInt(8).array();

  for (byte t : bytes) {

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

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