转载自https://www.cnblogs.com/hglibin/p/9001876.html

Java数组的十大方法
以下是Java Array的前10种方法。他们是来自stackoverflow的投票最多的问题。

  • 0.声明一个数组
  1. 123String[] aArray = new String[5];
  2. String[] bArray = {"a","b","c", "d", "e"};
  3. String[] cArray = new String[]{"a","b","c","d","e"};
  • 1.用Java打印数组
  1. 1234567int[] intArray = { 1, 2, 3, 4, 5 };
  2. String intArrayString = Arrays.toString(intArray);
  3. // print directly will print reference value
  4. System.out.println(intArray);
  5. // [I@7150bd4d
  6. System.out.println(intArrayString);
  7. // [1, 2, 3, 4, 5]
  • 2.从数组中创建一个ArrayList
  1. 1234String[] stringArray = { "a", "b", "c", "d", "e" };
  2. ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
  3. System.out.println(arrayList);
  4. // [a, b, c, d, e]
  • 3.检查数组是否包含某个值
  1. 1234String[] stringArray = { "a", "b", "c", "d", "e" };
  2. boolean b = Arrays.asList(stringArray).contains("a");
  3. System.out.println(b);
  4. // true
  • 4.连接两个数组
  1. 1234int[] intArray = { 1, 2, 3, 4, 5 };
  2. int[] intArray2 = { 6, 7, 8, 9, 10 };
  3. // Apache Commons Lang library
  4. int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2);
  • 5.内联声明一个数组
  1. 1method(new String[]{"a", "b", "c", "d", "e"});
  • 6.将提供的数组的元素连接成单个字符串
  1. 12345// containing the provided list of elements
  2. // Apache common lang
  3. String j = StringUtils.join(new String[] { "a", "b", "c" }, ", ");
  4. System.out.println(j);
  5. // a, b, c
  • 7.将ArrayList包含到数组中
  1. 123456String[] stringArray = { "a", "b", "c", "d", "e" };
  2. ArrayList<String> arrayList = new ArrayList<String>(Arrays.asList(stringArray));
  3. String[] stringArr = new String[arrayList.size()];
  4. arrayList.toArray(stringArr);
  5. for (String s : stringArr)
  6. System.out.println(s);
  • 8.将数组转换为集合
  1. 123Set<String> set = new HashSet<String>(Arrays.asList(stringArray));
  2. System.out.println(set);
  3. //[d, e, b, c, a]
  • 9.反转一个数组
  1. 1234int[] intArray = { 1, 2, 3, 4, 5 };
  2. ArrayUtils.reverse(intArray);
  3. System.out.println(Arrays.toString(intArray));
  4. //[5, 4, 3, 2, 1]
  • 10.删除数组的元素
  1. 123int[] intArray = { 1, 2, 3, 4, 5 };
  2. int[] removed = ArrayUtils.removeElement(intArray, 3);//create a new array
  3. System.out.println(Arrays.toString(removed));
  • 再多一个 – 将int转换为字节数组
  1. 1234byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();
  2. for (byte t : bytes) {
  3. System.out.format("0x%x ", t);
  4. }

转:https://www.programcreek.com/2013/09/top-10-methods-for-java-arrays/

版权声明:本文为sogeisetsu原创文章,遵循 CC 4.0 BY-SA 版权协议,转载请附上原文出处链接和本声明。
本文链接:https://www.cnblogs.com/sogeisetsu/articles/11873992.html2