陣列之間轉換和List轉換的總結

//將陣列轉為list

integer[
] i =
; arrays.
sort
(i);
//排序
list
list = arrays.
aslist
(i);
//將list轉為陣列
integer[
] j =
newinteger
[list.
size()
];list.
toarray
(j);

//list之間型別裝換，將integer型別轉換成string型別

list
integers = arrays.
aslist
(123
,456
,789);
list
strings = integers.
stream()
.map
(string:
:valueof)
.collect
(collectors.
tolist()
);

//將user型別的list，取出id轉為string型別

list
users =
newarraylist
<
>()
;list
strings = users.
stream()
.map
(users:
:getuserid)
.collect
(collectors.
tolist()
);

//將list裡面的數全都*2

list
integers = arrays.
aslist
(123
,456
,789);
list
mobiles = integers.
stream()
.map
(integer -
> integer *2)
.collect
(collectors.
tolist()
);

list

users = userdao.
getuser()
;user.
stream()
.foreach
(user -
> user.
setgender
("男"))
;

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