An array (array) Description of Java

Code Description:

1  PackageArray;2 3 Importjava.util.ArrayList;4 Importjava.util.Arrays;5 Importjava.util.List;6 7 /**8 * Instructions for using the array:9 * Content:Ten * 1, array instantiation; One * 2, array and ArrayList conversion; A * 3. Instantiate ArrayList via array - * Difference: - *--array ([]): The most efficient, but its capacity is fixed and can not be changed dynamically; the *--arraylist: Capacity can be dynamically increased, but sacrificing efficiency; -  * https://www.cnblogs.com/wangbin2188/p/6524200.html -  */ -  Public classArraydemo { +      Public Static voidMain (string[] args) { -         //Instantiation 1 +string[] Array =NewString[2]; AArray[0] = "AAA"; atARRAY[1] = "BBB"; -  -         //Instantiation 2 -String[] Array2 = {"A", "B", "C"}; -          for(String s:array2) { - System.out.println (s); in         } -  to //data element Fill value +Arrays.fill (Array2, "D"); -          for(String s:array2) { the System.out.println (s); *         } $         //The arrays method contains: sort (), BinarySearch (), Equals (), fill (), aslist ()Panax Notoginseng  -         //instantiate ArrayList with array theList List =NewArrayList (Arrays.aslist ("A", "B")); + System.out.println (list); A  theList List2 =arrays.aslist (array); + System.out.println (list2); -  $  $         //ArrayList convert to array - Arraydemo.listtoarray (); -  the         //array conversion to ArrayList - arraydemo.arraytolist ();Wuyi  the     } -  Wu     /** - * ArrayList converted to array About      */ $      Public Static voidListtoarray () { -list<string> list =NewArraylist<string>(); -List.add ("Wang Lihu"); -List.add ("Zhang San"); AList.add ("John Doe"); +         intSize =list.size (); thestring[] Array = (string[]) List.toarray (Newstring[size]); -          for(inti = 0; i < Array.Length; i++) { $ System.out.println (Array[i]); the         } the     } the  the     /** - * Array converted to ArrayList in      */ the      Public Static voidarraytolist () { thestring[] Array =NewString[3]; AboutArray[0] = "Wang Lihu"; theArray[1] = "Zhang San"; theARRAY[2] = "John Doe"; thelist<string> list =arrays.aslist (array); +          for(inti = 0; I < list.size (); i++) { - System.out.println (List.get (i)); the         }Bayi     } the}

Operation Result:

Abcddd[a, B][AAA, BBB] Wang Lihu Zhang Sanli Tiger Dick and Harry Process finished with exit code 0

An array (array) Description of Java