創(chuàng)建一個(gè)數(shù)組：

String[] a = new String[5]; String[] b = {“a”,”b”,”c”, “d”, “e”}; String[] c = new String[]{“a”,”b”,”c”,”d”,”e”};

1、打印數(shù)組

我們經(jīng)常使用for循環(huán)或者一些迭代器來(lái)打印出數(shù)組的所有元素，但我們也可以換個(gè)姿勢(shì)。

int array[] = {1,2,3,4,5}; System.out.println(array); //[I@1234be4e String arrStr = Arrays.toString(array); System.out.println(array); //[1,2,3,4,5];

2、創(chuàng)建ArrayList

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

3、檢查是否包含某個(gè)值

int array[] = {1,2,3,4,5}; boolean isContain= Arrays.asList(array).contains(5); System.out.println(isContain); // true

4、連接兩個(gè)數(shù)組

int[] array1 = { 1, 2, 3, 4, 5 }; int[] array2 = { 6, 7, 8, 9, 10 }; // Apache Commons Lang library int[] combinedIntArray = ArrayUtils.addAll(array1, array2);

5、在一行聲明一個(gè)數(shù)組

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

6、數(shù)組倒置

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

7、刪除某個(gè)元素

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

8、轉(zhuǎn)化為set

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

9、將Array List轉(zhuǎn)化為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);

10、將數(shù)組元素組成一個(gè)字符串

// Apache common lang String j = StringUtils.join(new String[] { "a", "b", "c" }, ", "); System.out.println(j); //a, b, c