Detailed explanation of Java arrays and sample code

Below are the 12 array operation methods that get the most votes in stackoverflow.

1. Declare an array

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

2. Output an array

 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]

3. Create an array list 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]

4. Check whether 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

5. Concatenate two arrays

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

6. Declare an inline array (Array inline)

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

7. Put the provided array element into a string

 // 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

8. Convert an array list 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);

9. Convert an array to set

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

10. Inverse an array

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

11. Remove elements from array

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

12. Convert integers to byte arrays

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

The above is a compilation of Java array information. We will continue to add relevant information in the future. Thank you for your support for this website!