y********o
发帖数: 2565 | 1 At the very bottom of the following page:
http://java.sun.com/docs/books/tutorial/collections/interfaces/collection.ht
ml
Suppose that c is known to contain only strings (perhaps because c is of typ
e Collection). The following snippet dumps the contents of c into a
newly allocated array of String whose length is identical to the number of e
lements in c.
String[] a = c.toArray(new String[0]);
The API doc for public T[] toArray(T[] a) says:
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g*****g
发帖数: 34805 | 2 don't make much difference, new String[5] is an array too.
typ
a
e
【在 y********o 的大作中提到】
: At the very bottom of the following page:
: http://java.sun.com/docs/books/tutorial/collections/interfaces/collection.ht
: ml
:
: Suppose that c is known to contain only strings (perhaps because c is of typ
: e Collection). The following snippet dumps the contents of c into a
: newly allocated array of String whose length is identical to the number of e
: lements in c.
: String[] a = c.toArray(new String[0]);
:
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y********o
发帖数: 2565 | 3 Thx, I was just curious about the capacity of the array at initialization.
It makes no difference if a.length <= c.size(), otherwise, you get null for
a[i] where i>c.size().
【在 g*****g 的大作中提到】
: don't make much difference, new String[5] is an array too.
:
: typ
: a
: e
|
m******t
发帖数: 2416 | 4 String[] a = c.toArray(new String[c.size()]);
is what I usually do.
for
【在 y********o 的大作中提到】
: Thx, I was just curious about the capacity of the array at initialization.
: It makes no difference if a.length <= c.size(), otherwise, you get null for
: a[i] where i>c.size().
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o******t
发帖数: 1144 | 5 but it is runtime too, right? I guess this String[0] is just a hint on type
【在 m******t 的大作中提到】
: String[] a = c.toArray(new String[c.size()]);
: is what I usually do.
:
:
: for
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m******t
发帖数: 2416 | 6
type
The idea is to make an array big enough that can be used for both a hint on
type and the actual container returned.
【在 o******t 的大作中提到】
: but it is runtime too, right? I guess this String[0] is just a hint on type
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