1. 声明一个数组
Java代码
String[] aArray =newString[5];
String[] bArray = {"a","b","c","d","e"};
String[] cArray =newString[]{"a","b","c","d","e"};
2. 输出一个数组
Java代码
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. 从一个数组创建数组列表
Java代码
String[] stringArray = {"a","b","c","d","e"};
ArrayList arrayList =newArrayList(Arrays.asList(stringArray));
System.out.println(arrayList);
// [a, b, c, d, e]
4. 检查一个数组是否包含某个值
Java代码
String[] stringArray = {"a","b","c","d","e"};
booleanb = Arrays.asList(stringArray).contains("a");
System.out.println(b);
// true
5. 连接两个数组
Java代码
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. 声明一个内联数组（Array inline）
Java代码
method(newString[]{"a","b","c","d","e"});
7. 把提供的数组元素放入一个字符串
Java代码
// containing the provided list of elements
// Apache common lang
String j = StringUtils.join(newString[] {"a","b","c"},", ");
System.out.println(j);
// a, b, c
8. 将一个数组列表转换为数组
Java代码
String[] stringArray = {"a","b","c","d","e"};
ArrayList arrayList =newArrayList(Arrays.asList(stringArray));
String[] stringArr =newString[arrayList.size()];
arrayList.toArray(stringArr);
for(String s : stringArr)
System.out.println(s);
9. 将一个数组转换为集（set）
Java代码
Set set =newHashSet(Arrays.asList(stringArray));
System.out.println(set);
//[d, e, b, c, a]
10. 逆向一个数组
Java代码
int[] intArray = {1,2,3,4,5};
ArrayUtils.reverse(intArray);
System.out.println(Arrays.toString(intArray));
//[5, 4, 3, 2, 1]
11. 移除数组中的元素
Java代码
int[] intArray = {1,2,3,4,5};
int[] removed = ArrayUtils.removeElement(intArray,3);//create a new array
System.out.println(Arrays.toString(removed));
12. 将整数转换为字节数组
Java代码
byte[] bytes = ByteBuffer.allocate(4).putInt(8).array();
for(bytet : bytes) {
System.out.format("0x%x ", t);
}
