blocks|key|1432451|text|不，你不能用foreach，|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|1432452|这主要是因为每个对象都是只读的，但也是因为您将覆盖循环中对象的引用。Java不是这样工作的。嗯，我不知道一种面向对象的语言，它在哪里起作用。|1432453|您可以用这个简单的例子来测试它：|1432454|String[]+strings+=+new+String[10];
for(String+s:+strings)
++++s+=+"This+won't+work!";

for+(String+s+:+strings)
++++System.out.println(s);|code-block|syntax|javascript|1432455|它会打印出来|1432456|null
null
null
null
null
null
null
null
null
null|1432457|通常的方法是使用普通的for-循环.|1432458|entityMap^0|0|E|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|10|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|11|8|@]|D|@]|E|$M|N]]|$1|O|3|P|5|6|7|12|8|@]|D|@]|E|$]]|$1|Q|3|R|5|L|7|13|8|@]|D|@]|E|$M|N]]|$1|S|3|T|5|6|7|14|8|@]|D|@]|E|$]]|$1|U|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|V|$]]

No, you can't use foreach. 
This is mainly because for each is read only, but also because you would overwrite the reference of the object in the loop. Java doesn't work this way. Well, I don't know one object oriented language, where this would work.

You could test it with this simple example:

<pre><code>String[] strings = new String[10];
for(String s: strings)
 s = "This won't work!";

for (String s : strings)
 System.out.println(s);
</code></pre>

It would print out

<pre><code>null
null
null
null
null
null
null
null
null
null
</code></pre>

The normal way to go is to use a normal for-loop.

blocks|key|4255461|text|不，这是不可能的，因为增强的for循环将提供对当前元素的引用。将一个新对象分配给引用不会将元素分配给数组。使用数组访问表达式向数组分配元素是无可替代的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4255462|您可以使用两个带有数组访问表达式的“传统”for循环来初始化数组。|4255463|for+(int+s+=+0;+s+<+SUITS;+s%2B%2B)
+++for+(int+c+=+0;+c+<+RANKS;+c%2B%2B)
+++++++cards[s][c]+=+new+Card(...);|code-block|syntax|javascript|4255464|使用数组初始化程序是可能的，但它会乏味、过于冗长和容易出错。|4255465|cards+=+new+Card[][]+{
++{new+Card(...),+new+Card(...),+...+},
++{new+Card(...),+new+Card(...),+...+},
++...};|4255466|有趣的是，由于2D数组是作为数组实现的，并且使用数组引用，所以可以使用增强的for循环初始化外部数组，只要内部数组是用“传统”循环初始化的。这是因为suit是cards中的数组，所以suit[c]是cards中的一个元素。|4255467|cards+=+new+Card[SUITS][RANKS];

for(Card[]+suit+:+cards)+{
++++for(int+c+=+0;+c+<+RANKS;+c%2B%2B)+{
++++++++suit[c]+=+new+Card(suitVar,+rankVar);
++++}
}|4255468|entityMap^0|E|3|0|L|3|0|0|0|0|12|3|22|4|27|5|2J|7|2R|5|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@$9|10|A|11|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|13|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|14|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|15|8|@$9|16|A|17|B|C]|$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]]|D|@]|E|$]]|$1|S|3|T|5|J|7|1G|8|@]|D|@]|E|$K|L]]|$1|U|3|-4|5|6|7|1H|8|@]|D|@]|E|$]]]|V|$]]

No, this is not possible, because an enhanced <code>for</code> loop will give a reference to the current element. Assigning a new object to the reference won't assign the element to the array. There is no substitute for using an array access expression to assign an element to an array.

You can use two "traditional" <code>for</code> loops with an array access expression to initialize the array.

<pre><code>for (int s = 0; s &lt; SUITS; s++)
 for (int c = 0; c &lt; RANKS; c++)
 cards[s][c] = new Card(...);
</code></pre>

It's possible to use an array initializer, but it would tedious, excessively verbose, and error-prone.

<pre><code>cards = new Card[][] {
 {new Card(...), new Card(...), ... },
 {new Card(...), new Card(...), ... },
 ...};
</code></pre>

Interestingly, because the 2D array is implemented as an array of arrays, and array references are used, the outer array can be initialized with an enhanced <code>for</code> loop, as long as the inner array is initialized with a "traditional" loop. This works because <code>suit</code> is an array in <code>cards</code>, so <code>suit[c]</code> is an element in <code>cards</code>.

<pre><code>cards = new Card[SUITS][RANKS];

for(Card[] suit : cards) {
 for(int c = 0; c &lt; RANKS; c++) {
 suit[c] = new Card(suitVar, rankVar);
 }
}
</code></pre>

blocks|key|1926553|text|对于这个特殊的例子，一个很好的策略是创建适合西装和级别的enum。然后，你可以通过循环这些来初始化一个甲板。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1926554|public+enum+Suit+{+CLUB,+DIAMOND,+HEART,+SPADE+}
public+enum+Rank+{
++++ACE,
++++TWO,
++++...
++++QUEEN,
++++KING
}|code-block|syntax|javascript|1926555|然后|1926556|List<Card>+deck+=+new+ArrayList(Suit.values().length+*+Rank.values.length);
for+(Suit+s:+Suit.values())+{
++++for+(Rank+r:+Rank.values())+{
++++++++deck.add(new+Card(s,+r));
++++}
}|1926557|这允许您在enum上使用增强的enum循环，而不是卡片本身的数组。它也能更好地表达你想要建模的系统。因此，它在很大程度上取决于具体情况，但这可以应用于不仅仅是带有西装和等级的牌。这是否适当，应视具体情况而定。|1926558|因此，要更直接地回答这个问题:不是你所做的方式，而是通过另一种(在这种情况下，更好的)模型，它成为可能。|1926559|entityMap^0|S|4|0|0|0|0|5|4|F|4|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|6|7|15|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|T|$]]

For this particular example, a good strategy would be to create <code>enum</code>s for suits and ranks. Then you can initialize a deck by looping over those.

<pre><code>public enum Suit { CLUB, DIAMOND, HEART, SPADE }
public enum Rank {
 ACE,
 TWO,
 ...
 QUEEN,
 KING
}
</code></pre>

Then

<pre><code>List&lt;Card&gt; deck = new ArrayList(Suit.values().length * Rank.values.length);
for (Suit s: Suit.values()) {
 for (Rank r: Rank.values()) {
 deck.add(new Card(s, r));
 }
}
</code></pre>

This allows you to use enhanced <code>for</code> loops over the <code>enum</code>s, rather than the array of cards itself. It's also a better representation of the system you're trying to model. As such, it's heavily dependent on the specific case, but this can be applied to more than just cards with a suit and rank. Whether this is appropriate should be determined on a case by case basis.

So to answer more directly: not the way you're doing it, but with an alternative (and in this case, better) model, it becomes possible.

In the following(wrong) code I want to inizialize the objects contained in the array <code>cards</code> to create a deck. Is there a way to do it through an enhanced for loop or have I to use the "standard" for loop?

<pre><code>cards = new Card[SUITS][RANKS];

for(Card[] suit : cards) {
 for(Card card : suit) {
 card = new Card(suitVar, rankVar);
 }
}
</code></pre>

Is it possible to initialize the objects in an array through an enhanced for loop?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在下面的(错误)代码中，我希望初始化数组cards中包含的对象，以创建一个桥面。有什么方法可以通过增强的for循环来完成，还是让我使用“标准”for循环？cards = new Card[SUITS][RANKS];for(Card[] suit : cards) {    for(Card card : suit) ...

问是否可以通过增强的for循环初始化数组中的对象？
EN

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问是否可以通过增强的for循环初始化数组中的对象？EN