Java?? ?? ???? ??? ???? ??: 1. ???? ?? toArray ???? ?????. ?? ??? "Object[] toArray();"???. 2. ???? ???? toArray ???? ?????. ?? ??? ??? ????. "T[] toArray (T[] a);".

?? ??: "Java ??? ????"

Java??? ??? ?? ?? ??? ??? ????? ?? ??? ???. ???? ??? ??? ???? ??? ?????? ?? ????? ?? ?????.

List? ??? ????? List? toArray() ?? toArray(T[] a) ???? ??? ? ????.

??? ??? ??

??? ??? ????? toArray ???? ??? ? ????.

???? ? ?? ????? ???? ????.

????? ?? ????? ?? ? ?? ???? ?????.

Object[] toArray();
<T> T[] toArray(T[] a);

2.1 . ???? ?? toArray ???

Object[] toArray();

? ???? List? Object[] ??? ?? ?????.

Java ???? ? ??? ?????.

???? ?? ???? ?? ?????.

??? ??? ???? ? ??? ???? ????.

??? ??? ?? ?? ??? ??? ????. ??? ????

cannot Convert Object[] to String[]:

List<String> strList = new ArrayList<>();
strList.add("list-a");
strList.add("list-b");
String[] strArray = (String[]) strList.toArray();

??? ?? ??? ??? ????.

Exception in thread "main" java.lang.ClassCastException: 
[Ljava.lang.Object; cannot be cast to [Ljava.lang.String;

?? ??? ?? Object[]? ?????.

List<String> strList = new ArrayList<>();
Object[] strArray = strList.toArray();

?? ??? ?? ????? ??? ? ????.

int[] ?? ??? ???? ??

int[]? Integer[]? ??? ???.

??? ?? ??? ??? ????.

<T> T[] toArray(T[] a);

?? ??? ??

???? ??? ??? ???

? ??? ?????. List strList.size( ) ??, ?? ?? ??

? ??? ??:

List<String> strList = new ArrayList<>();
strList.add("list-a");
strList.add("list-b");
String[] strArray = strList.toArray(new String[strList.size()]);

2.3.1.size < strList.size()

?? size=0?? ????

? strList?? ????. size()=2,

??? ?? ??? ??? ????.

List<String> strList = new ArrayList<>();
strList.add("list-a");
strList.add("list-b");
String[] strArray1 = new String[size];
String[] strArray2 = strList.toArray(strArray1);

??? strArray2? strArray1? ??? ??? ????.

2.3.2.size = strList.size()

?? size=strList.size()? ????,

?? ?? ??? ??? ????.

String[] strArray1 = new String[0];

??? strArray2? strArray1? ??? ?????.

??? ?? ? ???

?? ?? strArray? ??? ???? ?????.

String[] strArray1 = new String[strList.size()];

2.3.3.size > strList.size()

?? size=strList.size()? ?????. +1,

??? ?? ??? ??? ????.

String[] strArray = strList.toArray(new String[strList.size()]);
String[] strArray = new String[strList.size()];
strList.toArray(strArray);

??? strArray2? strArray1? ??? ?????.

??? ??? ??? ??? null??,

??? ? ?? ??? ?? ??

??? ??? ?? ??? ?? null? ?????.

?, strArray1[strList.size()]=null,

??? ???? ??? ?? ??,

strList.size( )+2? ???? ??? ??????.

??? ??? ? ?? ??? null???.

? ?? ????? ?? ??? ???

? ?????! !

? ??? Java?? ??? ??? ???? ??? ??????? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!