blocks|key|3148598|text|这就是所谓的varargs有关更多详细信息，请参阅链接here|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3148599|在以前的java版本中，接受任意数量的值的方法需要在调用该方法之前创建一个数组并将这些值放入该数组中。例如，下面是如何使用MessageFormat类来格式化消息的：|3148600|Object[]+arguments+=+{
++++new+Integer(7),
++++new+Date(),
++++"a+disturbance+in+the+Force"
};
++++String+result+=+MessageFormat.format(
++++++++"At+{1,time}+on+{1,date},+there+was+{2}+on+planet+"
+++++++++%2B+"{0,number,integer}.",+arguments);|code-block|syntax|javascript|3148601|多个参数必须在一个数组中传递，这仍然是事实，但varargs功能会自动执行并隐藏该过程。此外，它与现有的API向上兼容。因此，例如，MessageFormat.format方法现在有这样的声明：|3148602|public+static+String+format(String+pattern,
++++++++++++++++++++++++++++Object...+arguments);|3148603|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/1,5.0/docs/guide/language/varargs.html^0|R|4|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|6|7|10|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|11|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|12|8|@]|9|@]|C|$]]|$1|M|3|N|5|H|7|13|8|@]|9|@]|C|$I|J]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

This is known as varargs see the link <a href="http://download.oracle.com/javase/1,5.0/docs/guide/language/varargs.html">here</a> for more details

In past java releases, a method that took an arbitrary number of values required you to create an array and put the values into the array prior to invoking the method. For example, here is how one used the MessageFormat class to format a message:

<pre><code>Object[] arguments = {
 new Integer(7),
 new Date(),
 "a disturbance in the Force"
};
 String result = MessageFormat.format(
 "At {1,time} on {1,date}, there was {2} on planet "
 + "{0,number,integer}.", arguments);
</code></pre>

It is still true that multiple arguments must be passed in an array, but the varargs feature automates and hides the process. Furthermore, it is upward compatible with preexisting APIs. So, for example, the MessageFormat.format method now has this declaration:

<pre><code>public static String format(String pattern,
 Object... arguments);
</code></pre>

blocks|key|254280|text|你可以写一个方便的方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|254281|public+PrintStream+print(String+format,+Object...+arguments)+{
++++return+System.out.format(format,+arguments);
}|code-block|syntax|javascript|254282|但是正如您所看到的，您只是简单地重命名了format+(或printf)。|offset|length|style|CODE|254283|下面是你如何使用它：|254284|private+void+printScores(Player...+players)+{
++++for+(int+i+=+0;+i+<+players.length;+%2B%2Bi)+{
++++++++Player+player+=+players[i];
++++++++String+name+++=+player.getName();
++++++++int++++score++=+player.getScore();
++++++++//+Print+name+and+score+followed+by+a+newline
++++++++System.out.format("%25s:+%25d%25n",+name,+score);
++++}
}

//+Print+a+single+player,+3+players,+and+all+players
printScores(player1);
System.out.println();
printScores(player2,+player3,+player4);
System.out.println();
printScores(playersArray);

//+Output
Abe:+11

Bob:+22
Cal:+33
Dan:+44

Abe:+11
Bob:+22
Cal:+33
Dan:+44|254285|注意，还有一个类似的System.out.printf方法，它的行为也是一样的，但是如果您看一下实现，printf只调用format，所以您也可以直接使用format。|254286|254287|Varargs|unordered-list-item|254288|PrintStream#format(String+format,+Object...+args)|254289|PrintStream#printf(String+format,+Object...+args)|254290|254291|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/1.5.0/docs/guide/language/varargs.html|1|http://download.oracle.com/javase/7/docs/api/java/io/PrintStream.html#format%2528java.lang.String,%2520java.lang.Object...%2529|2|http://download.oracle.com/javase/7/docs/api/java/io/PrintStream.html#printf%2528java.lang.String,%2520java.lang.Object...%2529^0|0|0|K|6|T|6|0|0|0|A|H|1F|6|1O|6|25|6|0|0|0|7|0|0|0|1D|0|1D|1|0|0|1D|0|1D|2|0|0^^$0|@$1|2|3|4|5|6|7|1D|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|1E|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|1F|8|@$I|1G|J|1H|K|L]|$I|1I|J|1J|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|1K|8|@]|9|@]|A|$]]|$1|O|3|P|5|D|7|1L|8|@]|9|@]|A|$E|F]]|$1|Q|3|R|5|6|7|1M|8|@$I|1N|J|1O|K|L]|$I|1P|J|1Q|K|L]|$I|1R|J|1S|K|L]|$I|1T|J|1U|K|L]]|9|@]|A|$]]|$1|S|3|-4|5|6|7|1V|8|@]|9|@]|A|$]]|$1|T|3|U|5|V|7|1W|8|@]|9|@$I|1X|J|1Y|1|1Z]]|A|$]]|$1|W|3|X|5|V|7|20|8|@$I|21|J|22|K|L]]|9|@$I|23|J|24|1|25]]|A|$]]|$1|Y|3|Z|5|V|7|26|8|@$I|27|J|28|K|L]]|9|@$I|29|J|2A|1|2B]]|A|$]]|$1|10|3|-4|5|6|7|2C|8|@]|9|@]|A|$]]|$1|11|3|-4|5|6|7|2D|8|@]|9|@]|A|$]]]|12|$13|$5|14|15|16|A|$17|18]]|19|$5|14|15|16|A|$17|1A]]|1B|$5|14|15|16|A|$17|1C]]]]

You could write a convenience method:

<pre><code>public PrintStream print(String format, Object... arguments) {
 return System.out.format(format, arguments);
}
</code></pre>

But as you can see, you've simply just renamed <code>format</code> (or <code>printf</code>).

Here's how you could use it:

<pre><code>private void printScores(Player... players) {
 for (int i = 0; i &lt; players.length; ++i) {
 Player player = players[i];
 String name = player.getName();
 int score = player.getScore();
 // Print name and score followed by a newline
 System.out.format("%s: %d%n", name, score);
 }
}

// Print a single player, 3 players, and all players
printScores(player1);
System.out.println();
printScores(player2, player3, player4);
System.out.println();
printScores(playersArray);

// Output
Abe: 11

Bob: 22
Cal: 33
Dan: 44

Abe: 11
Bob: 22
Cal: 33
Dan: 44
</code></pre>

Note there's also the similar <code>System.out.printf</code> method that behaves the same way, but if you peek at the implementation, <code>printf</code> just calls <code>format</code>, so you might as well use <code>format</code> directly.

<ul>
<li><a href="http://docs.oracle.com/javase/1.5.0/docs/guide/language/varargs.html" rel="noreferrer">Varargs</a></li>
<li><a href="http://download.oracle.com/javase/7/docs/api/java/io/PrintStream.html#format%28java.lang.String,%20java.lang.Object...%29" rel="noreferrer"><code>PrintStream#format(String format, Object... args)</code></a></li>
<li><a href="http://download.oracle.com/javase/7/docs/api/java/io/PrintStream.html#printf%28java.lang.String,%20java.lang.Object...%29" rel="noreferrer"><code>PrintStream#printf(String format, Object... args)</code></a></li>
</ul>

blocks|key|3148653|text|看看varargs上的Java指南。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3148654|您可以创建如下所示的方法。只需调用System.out.printf而不是System.out.println(String.format(...。|style|CODE|3148655|public+static+void+print(String+format,+Object...+args)+{
++++System.out.printf(format,+args);
}|code-block|syntax|javascript|3148656|或者，如果您想输入尽可能少的内容，也可以只使用static+import。这样你就不必创建你自己的方法了：|3148657|import+static+java.lang.System.out;

out.printf("Numer+of+apples:+%25d",+10);|3148658|entityMap|0|LINK|mutability|MUTABLE|url|http://download.oracle.com/javase/1,5.0/docs/guide/language/varargs.html|1|http://download.oracle.com/javase/1,5.0/docs/guide/language/static-import.html^0|2|7|0|0|H|H|11|10|0|0|N|D|1|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@$A|11|B|12|1|13]]|C|$]]|$1|D|3|E|5|6|7|14|8|@$A|15|B|16|F|G]|$A|17|B|18|F|G]]|9|@]|C|$]]|$1|H|3|I|5|J|7|19|8|@]|9|@]|C|$K|L]]|$1|M|3|N|5|6|7|1A|8|@]|9|@$A|1B|B|1C|1|1D]]|C|$]]|$1|O|3|P|5|J|7|1E|8|@]|9|@]|C|$K|L]]|$1|Q|3|-4|5|6|7|1F|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]|Y|$5|T|U|V|C|$W|Z]]]]

Take a look at the Java guide on <a href="http://download.oracle.com/javase/1,5.0/docs/guide/language/varargs.html" rel="nofollow">varargs</a>. 

You can create a method as shown below. Simply call <code>System.out.printf</code> instead of <code>System.out.println(String.format(...</code>.

<pre><code>public static void print(String format, Object... args) {
 System.out.printf(format, args);
}
</code></pre>

Alternatively, you can just use a <a href="http://download.oracle.com/javase/1,5.0/docs/guide/language/static-import.html" rel="nofollow">static import</a> if you want to type as little as possible. Then you don't have to create your own method:

<pre><code>import static java.lang.System.out;

out.printf("Numer of apples: %d", 10);
</code></pre>

blocks|key|252169|text|下面将创建字符串类型的可变长度参数集：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|252170|print(String+arg1,+String...+arg2)|code-block|syntax|javascript|252171|然后，您可以将arg2引用为字符串数组。这是Java5中的一个新特性。|offset|length|style|CODE|252172|entityMap^0|0|0|7|4|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

The following will create a variable length set of arguments of the type of string:

<pre><code>print(String arg1, String... arg2)
</code></pre>

You can then refer to <code>arg2</code> as an array of Strings. This is a new feature in Java 5.

blocks|key|2934214|text|变量参数必须是函数声明中指定的最后一个参数。如果您试图在变量参数之后指定另一个参数，编译器将会报错，因为无法确定有多少参数实际属于变量参数。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2934215|void+print(final+String+format,+final+String...+arguments)+{
++++System.out.format(+format,+arguments+);
}|code-block|syntax|javascript|2934216|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

The variable arguments must be the last of the parameters specified in your function declaration. If you try to specify another parameter after the variable arguments, the compiler will complain since there is no way to determine how many of the parameters actually belong to the variable argument.

<pre><code>void print(final String format, final String... arguments) {
 System.out.format( format, arguments );
}
</code></pre>

blocks|key|252219|text|这只是上面提供的答案的一个扩展。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|252220|method.|252221|Variable参数中只能有一个变量参数(|unordered-list-item|252222|)必须是最后一个参数。|ordered-list-item|252223|252224|252225|清楚地解释了here和使用变量参数时要遵循的规则。|offset|length|style|BOLD|252226|entityMap|0|LINK|mutability|MUTABLE|url|http://www.javatpoint.com/varargs^0|0|0|0|0|0|0|D|4|6|4|0|0^^$0|@$1|2|3|4|5|6|7|Z|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|10|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|11|8|@]|9|@]|A|$]]|$1|G|3|H|5|I|7|12|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|13|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|14|8|@]|9|@]|A|$]]|$1|L|3|M|5|6|7|15|8|@$N|16|O|17|P|Q]]|9|@$N|18|O|19|1|1A]]|A|$]]|$1|R|3|-4|5|6|7|1B|8|@]|9|@]|A|$]]]|S|$T|$5|U|V|W|A|$X|Y]]]]

This is just an extension to above provided answers.

<ol>
<li>There can be only one variable argument in the method.</li>
<li>Variable argument (varargs) must be the last argument.</li>
</ol>

Clearly explained <a href="http://www.javatpoint.com/varargs" rel="nofollow">here</a> and rules to follow to use Variable Argument.

blocks|key|3148878|text|在调用函数时，可以在函数中传递所有类似的类型值。在函数定义中，放入一个数组，这样所有传递的值都可以在该数组中进行收集。例如。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|3148879|static+void+demo+(String+...+stringArray)+{
++your+code+goes+here+where+read+the+array+stringArray
}|code-block|syntax|javascript|3148880|entityMap^0|R|4|Z|2|1K|6|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|U|8|@]|D|@]|E|$]]]|L|$]]

You can pass all similar type values in the function while calling it.
In the function definition put a array so that all the passed values can be collected in that array.
e.g. 
.

<pre><code>static void demo (String ... stringArray) {
 your code goes here where read the array stringArray
}
</code></pre>

For example, Java's own <code>String.format()</code> supports a variable number of arguments.

<pre><code>String.format("Hello %s! ABC %d!", "World", 123);
//=&gt; Hello World! ABC 123!
</code></pre>

How can I make my own function that accepts a variable number of arguments?

<hr>

Follow-up question:

I'm really trying to make a convenience shortcut for this:

<pre><code>System.out.println( String.format("...", a, b, c) );
</code></pre>

So that I can call it as something less verbose like this:

<pre><code>print("...", a, b, c);
</code></pre>

How can I achieve this?

How can I create a Java method that accepts a variable number of arguments?

编译器

Java

例如，Java自己的String.format()支持可变数量的参数。String.format("Hello %s! ABC %d!", "World", 123);//=> Hello World! ABC 123!如何让我自己的函数接受可变数量的参数？后续问题：我真的在试着为这个做一个方便的快捷方式：System...

问如何创建接受可变数量参数的Java方法？
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