摘要:本文分享了关于Java数组最*的11大方法,帮助你解决工作流程问题,无论是运用在团队环境或是在私人项目中,你都可以直接拿来用。
本文分享了关于Java数组最*的11大方法,帮助你解决工作流程问题,无论是运用在团队环境或是在私人项目中,你都可以直接拿来用!
0. 声明一个数组(Declare an array)
1
2
3
|
String[] aArray = new String[5];
String[] bArray = { "a" , "b" , "c" , "d" , "e" };
String[] cArray = new String[]{ "a" , "b" , "c" , "d" , "e" };
|
1. 在Java中输出一个数组(Print an array in Java)
1
2
3
4
5
6
7
8
9
|
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] |
2. 从数组中创建数组列表(Create an ArrayList from an array)
1
2
3
4
|
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] |
3. 检查数组中是否包含特定值(Check if an array contains a certain value)
1
2
3
4
|
String[] stringArray = { "a" , "b" , "c" , "d" , "e" };
boolean b = Arrays.asList(stringArray).contains( "a" );
System.out.println(b); // true |
4. 连接两个数组( Concatenate two arrays)
1
2
3
4
|
int[] intArray = { 1, 2, 3, 4, 5 }; int[] intArray2 = { 6, 7, 8, 9, 10 }; // Apache Commons Lang library int[] combinedIntArray = ArrayUtils.addAll(intArray, intArray2); |
5. 声明一个数组内链(Declare an array inline )
1
|
method( new String[]{ "a" , "b" , "c" , "d" , "e" });
|
6. 将数组元素加入到一个独立的字符串中(Joins the elements of the provided array into a single String)
1
2
3
4
5
|
// 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 |
7. 将数组列表转换成一个数组 (Covnert an ArrayList to an array)
1
2
3
4
5
6
|
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);
|
8. 将数组转换成一个集合(Convert an array to a set)
1
2
3
|
Set<String> set = new HashSet<String>(Arrays.asList(stringArray));
System.out.println(set); //[d, e, b, c, a] |
9. 反向数组(Reverse an array)
1
2
3
4
|
int[] intArray = { 1, 2, 3, 4, 5 }; ArrayUtils.reverse(intArray); System.out.println(Arrays.toString(intArray)); //[5, 4, 3, 2, 1] |
10. 删除数组元素(Remove element of an array)
1
2
3
|
int[] intArray = { 1, 2, 3, 4, 5 }; int[] removed = ArrayUtils.removeElement(intArray, 3); //create a new array
System.out.println(Arrays.toString(removed)); |
One more – convert int to byte array
1
2
3
4
5
|
byte[] bytes = ByteBuffer.allocate(4).putInt(8).array(); for (byte t : bytes) {
System.out.format( "0x%x " , t);
} |
英文出自:
Programcreek