java数组的12个方法

一时失言乱红尘 2022-07-15 04:09 119阅读 0赞

**最近再微信上看见一篇关于java数组操作的12个方法，特分享一下：**

1.  声明一个数组   
  
  
Java代码   
String\[\] aArray = new String\[5\];    
String\[\] bArray = \{"a","b","c", "d", "e"\};    
String\[\] cArray = new String\[\]\{"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<String> arrayList = new ArrayList<String>(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" \};    
boolean b = 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(new String\[\]\{"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(new String\[\] \{ "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<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.  将一个数组转换为集（set）   
  
  
  
  
Java代码   
Set<String> set = new HashSet<String>(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 (byte t : bytes) \{    
   System.out.format("0x%x ", t);    
\}