blocks|key|1841888|text|在这种情况下，您不需要throws+Exception，因为ArithmeticException是一个RuntimeException，编译器不知道它会被抛出，所以它不会强迫您处理它。请参见：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1841889|​|1841890|📷|atomic|1841891|1841892|在需要这样做的情况下，如果您有一个不是运行时异常的异常，并且您没有围绕可能抛出异常的行使用try-catch子句，则必须声明该方法为throws+ThatException。|1841893|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/lang/ArithmeticException.html|1|2|IMAGE|IMMUTABLE|imageUrl|https://developer.qcloudimg.com/http-save/yehe-900000/dc0466710b1356e762241d2037eaa46b.jpg|imageAlt^0|B|G|U|J|1G|G|U|J|0|1G|G|1|0|0|0|1|2|0|0|1U|K|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@$9|19|A|1A|1|1B]|$9|1C|A|1D|1|1E]]|E|$]]|$1|F|3|G|5|6|7|1F|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1G|8|@]|D|@$9|1H|A|1I|1|1J]]|E|$]]|$1|K|3|G|5|6|7|1K|8|@]|D|@]|E|$]]|$1|L|3|M|5|6|7|1L|8|@$9|1M|A|1N|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|1O|8|@]|D|@]|E|$]]]|O|$P|$5|Q|R|S|E|$T|U]]|V|$5|Q|R|S|E|$T|U]]|W|$5|X|R|Y|E|$Z|10|11|-4]]]]

You don't need to <code>throws Exception</code> in this case because <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/ArithmeticException.html" rel="nofollow noreferrer"><code>ArithmeticException</code></a> is a <a href="http://docs.oracle.com/javase/7/docs/api/java/lang/ArithmeticException.html" rel="nofollow noreferrer"><code>RuntimeException</code></a>, the compiler doesn't know it'll be thrown, so it doesn't force you to deal with it. See:

<img src="https://i.stack.imgur.com/K85DP.jpg" alt="enter image description here">

Cases where you should do that, if you have an exception that's not a runtime exception, and you don't surround the line that might throw the exception with try-catch clause, then you'll have to declare the method to be <code>throws ThatException</code>.

blocks|key|843091|text|在这里游荡的是什么，在这个代码的第1行中，“抛出异常”到底做了什么？|type|blockquote|depth|inlineStyleRanges|entityRanges|data|843092|它将责任交给函数的调用方，这种方法可以抛出异常，您必须处理它。|unstyled|843093|而且，在您的示例中，它将从该方法抛出一个RuntimeException，因此，不需要声明异常的方法。这就是为什么即使你删除了抛出的异常部分，它也能工作。|offset|length|style|CODE|843094|如果该方法将抛出一个已检查的异常，如果在方法本身中不处理该异常，则必须在方法签名中声明抛出该异常。|843095|entityMap^0|0|0|K|G|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$]]|$1|E|3|F|5|D|7|Q|8|@$G|R|H|S|I|J]]|9|@]|A|$]]|$1|K|3|L|5|D|7|T|8|@]|9|@]|A|$]]|$1|M|3|-4|5|D|7|U|8|@]|9|@]|A|$]]]|N|$]]

<blockquote>
 here what am wandering is, in line 1 of this code "throws Exception"
 what exactly does?
</blockquote>

It gave the responsibility to the caller of the function, that, this method, can throws an Exception, You [Caller] have to handle it.

And, In your case, It's a <code>RuntimeException</code> will be thrown from that method, so, no need to declare the method with Exception. That's why even though if you removed that throws Exception part, It works. 

If the method will throw a checked Exception, and if you don't handle it inside the method itself, you have declare to throw that exception in the method signature.

blocks|key|843112|text|在方法的签名中使用“calls”来通知“调用此函数的父方法/方法”该函数“可能”抛出异常，而“父”方法/调用方应该处理它。是的，就像@maroun+Maroun所说的，“在目前的情况下，抛出是没有必要的”|type|blockquote|depth|inlineStyleRanges|entityRanges|data|843113|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|E|8|@]|9|@]|A|$]]|$1|B|3|-4|5|C|7|F|8|@]|9|@]|A|$]]]|D|$]]

<blockquote>
 "throws" is used in the signature of a method to inform the "parent
 method/method which calls this function" that this function "might"
 throw an exception, and the "parent" method/caller should handle it. And yes, as @maroun Maroun puts it, "in the current case, throws is unncesssary"
</blockquote>

blocks|key|1563835|text|in+line+1+of+this+code+"throws+Exception"+what+exactly+does?|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1563836|tells关键字告诉编译器具有异常条件的具有抛出关键字的方法，它不会处理该异常。任何方法都有责任调用带抛出关键字的方法来处理该异常。|unstyled|1563837|在这种情况下，the+()抛出异常，而不处理异常条件。在主要情况下，您已经调用了tryIt()，所以main有责任处理tryIt()抛出异常的未处理异常。|1563838|Where+it+will+be+effective?+Is+it+necessary+in+this+code?|1563839|当您希望使用适当的try+(选中的异常类型)调用您的方法时，它是有效的。|1563840|在这段代码中没有必要，因为在您的代码中，您得到的是java.lang.ArithmeticException:+/零异常，即RuntimeException(未检查类型)编译器不会抱怨没有处理它。|1563841|有关选中和未选中异常的详细信息，请参阅检查异常和未检查异常。|offset|length|1563842|entityMap|0|LINK|mutability|MUTABLE|url|http://javapapers.com/core-java/java-exception/explain-type-of-exceptions-or-checked-vs-unchecked-exceptions-in-java/^0|0|0|0|0|0|0|J|A|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|11|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|12|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|13|8|@]|9|@]|A|$B|C]]|$1|K|3|L|5|F|7|14|8|@]|9|@]|A|$]]|$1|M|3|N|5|F|7|15|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|16|8|@]|9|@$Q|17|R|18|1|19]]|A|$]]|$1|S|3|-4|5|F|7|1A|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]]]

<pre><code>in line 1 of this code "throws Exception" what exactly does?
</code></pre>

throws keyword tells the compiler that method with throws keyword having exceptional condition and it is not going to handle that exception. It is the responsibility of any method who called the method with throws keyword to handle that exception.

In you case tryit()throws Exception not handling the exceptional condition. In main you have called tryIt() so it is the responsibility of main to handle the unhandle exception of tryIt()throws Exception.

<pre><code>Where it will be effective? Is it necessary in this code?
</code></pre>

It is effective when you want your method to be called using proper try catch(Checked type of exception).

It is not necessary in this code because in your code you are getting java.lang.ArithmeticException: / by zero exception which is RuntimeException(Un Checked type) compiler won't complain about not handling it. 

for more information in checked and unchecked exception see <a href="http://javapapers.com/core-java/java-exception/explain-type-of-exceptions-or-checked-vs-unchecked-exceptions-in-java/" rel="nofollow">Checked and Unchecked Exception</a>

This is my code

<pre><code>static void tryit() throws Exception
{
 System.out.println(10 / 0);
}

public static void main(String[] args) 
{
 try {
 tryit();

 } catch (Exception e) {
 System.out.println("Exception caught in main");
 }
}
</code></pre>

here what am wandering is, in line 1 of this code <code>throws Exception</code> what exactly does? 
Even if I didn't use that also I got same output as

<blockquote>
 Output : Exception caught in main
</blockquote>

Where it will be effective? Is it necessary in this code?

What for the "throws" clause is used here and what if not used?

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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这是我的密码static void tryit() throws Exception{      System.out.println(10 / 0);}public static void main(String[] args) {    try {        tryit();    } catch (Excep...

问这里使用的是什么“抛出”子句，如果不使用呢？
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问这里使用的是什么“抛出”子句，如果不使用呢？EN

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问这里使用的是什么“抛出”子句，如果不使用呢？
EN