blocks|key|2772891|text|NumberFormatException扩展了RuntimeException，这是一个不需要捕获的未检查异常。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2772892|​|2772893|📷|atomic|2772894|2772895|摘录自Java教程|BOLD|2772896|2772897|因为Java编程语言不需要方法来捕获或指定未检查的异常(RuntimeException、Error及其子类)，所以程序员可能倾向于编写只抛出未检查的异常的代码，或者使所有的异常子类继承自RuntimeException。这两种快捷方式都允许程序员编写代码，而无需担心编译器错误，也无需费心指定或捕获任何异常。|blockquote|2772898|2772899|2772900|NumberFormatException+Api+Docs|2772901|entityMap|0|IMAGE|mutability|IMMUTABLE|imageUrl|https://ask.qcloudimg.com/http-save/yehe-900000/2c2901a3da401e47c37198f25065a014.png|imageAlt|1|LINK|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/lang/NumberFormatException.html^0|0|L|O|G|0|0|0|1|0|0|0|0|9|0|0|0|0|0|0|U|1|0^^$0|@$1|2|3|4|5|6|7|1A|8|@$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1F|8|@]|D|@]|E|$]]|$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|@$9|1M|A|1N|B|N]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|1O|8|@]|D|@]|E|$]]|$1|P|3|Q|5|R|7|1P|8|@]|D|@]|E|$]]|$1|S|3|-4|5|6|7|1Q|8|@]|D|@]|E|$]]|$1|T|3|-4|5|6|7|1R|8|@]|D|@]|E|$]]|$1|U|3|V|5|6|7|1S|8|@]|D|@$9|1T|A|1U|1|1V]]|E|$]]|$1|W|3|-4|5|6|7|1W|8|@]|D|@]|E|$]]]|X|$Y|$5|Z|10|11|E|$12|13|14|-4]]|15|$5|16|10|17|E|$18|19]]]]

<code>NumberFormatException</code> extends <code>RuntimeException</code> which is an unchecked exception that does not need to be caught.

<img src="https://i.stack.imgur.com/VQ0yN.png" alt="enter image description here">

Excerpt from the Java Tutorial

<blockquote>
 Because the Java programming language does not require methods to
 catch or to specify unchecked exceptions (RuntimeException, Error, and
 their subclasses), programmers may be tempted to write code that
 throws only unchecked exceptions or to make all their exception
 subclasses inherit from RuntimeException. Both of these shortcuts
 allow programmers to write code without bothering with compiler errors
 and without bothering to specify or to catch any exceptions.
 <a href="http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html" rel="nofollow noreferrer">Full Article</a>
</blockquote>

<a href="http://docs.oracle.com/javase/7/docs/api/java/lang/NumberFormatException.html" rel="nofollow noreferrer">NumberFormatException Api Docs</a>

blocks|key|4238458|text|从Java+language+spec|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|4238459|4238460|未检查的异常类是运行时异常类和错误类。|blockquote|4238461|4238462|4238463|换句话说，每个Throwable都是一个RuntimeException或子类，每个Throwable都是一个Error或子类。它们可以被捕获，但捕获或throws不是强制性的。|style|CODE|4238464|4238465|检查的异常类是除未检查的异常类之外的所有异常类。也就是说，检查的异常类是Throwable的所有子类，而不是RuntimeException及其子类和Error及其子类。|4238466|4238467|4238468|换句话说，每隔一个Throwable。它们必须被抛出(throws)或被接住。|4238469|NumberFormatException扩展了RuntimeException，因此它是未检查的异常类之一，并且不需要在方法中捕获或抛出。|4238470|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/specs/jls/se7/html/jls-11.html#jls-11.1.1^0|1|I|0|0|0|0|0|0|K|G|1J|5|24|6|0|0|0|0|0|9|9|R|6|0|0|L|O|G|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@$A|15|B|16|1|17]]|C|$]]|$1|D|3|-4|5|6|7|18|8|@]|9|@]|C|$]]|$1|E|3|F|5|G|7|19|8|@]|9|@]|C|$]]|$1|H|3|-4|5|6|7|1A|8|@]|9|@]|C|$]]|$1|I|3|-4|5|6|7|1B|8|@]|9|@]|C|$]]|$1|J|3|K|5|6|7|1C|8|@$A|1D|B|1E|L|M]|$A|1F|B|1G|L|M]|$A|1H|B|1I|L|M]]|9|@]|C|$]]|$1|N|3|-4|5|6|7|1J|8|@]|9|@]|C|$]]|$1|O|3|P|5|G|7|1K|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|1L|8|@]|9|@]|C|$]]|$1|R|3|-4|5|6|7|1M|8|@]|9|@]|C|$]]|$1|S|3|T|5|6|7|1N|8|@$A|1O|B|1P|L|M]|$A|1Q|B|1R|L|M]]|9|@]|C|$]]|$1|U|3|V|5|6|7|1S|8|@$A|1T|B|1U|L|M]|$A|1V|B|1W|L|M]]|9|@]|C|$]]|$1|W|3|-4|5|6|7|1X|8|@]|9|@]|C|$]]]|X|$Y|$5|Z|10|11|C|$12|13]]]]

From the <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-11.html#jls-11.1.1" rel="nofollow">Java language spec</a>:

<blockquote>
 The unchecked exception classes are the runtime exception classes and the error classes.
</blockquote>

In other words, every Throwable, that is a <code>RuntimeException</code> or a subclass and every Throwable, that is an <code>Error</code> or a subclass. They can be catched but catching or <code>throws</code> is not mandatory.

<blockquote>
 The checked exception classes are all exception classes other than the unchecked exception classes. That is, the checked exception classes are all subclasses of Throwable other than RuntimeException and its subclasses and Error and its subclasses.
</blockquote>

In other words, every other <code>Throwable</code>. They have to be thrown (<code>throws</code>) or catched.

<code>NumberFormatException</code> extends <code>RuntimeException</code> and therefore it is one of the unchecked exception classes and doesn't have to be catched or thrown be the method.

blocks|key|456633|text|NumberFormatException是所谓的未检查异常，因为它是RuntimeException的一个子类型。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|456634|在java中，未检查异常也可以在没有try-catch的情况下编译。|456635|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/1.4.2/docs/api/java/lang/NumberFormatException.html^0|0|L|Z|G|0|L|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]|$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]]|E|$]]|$1|F|3|G|5|6|7|X|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]]]

<a href="http://docs.oracle.com/javase/1.4.2/docs/api/java/lang/NumberFormatException.html" rel="nofollow"><code>NumberFormatException</code></a> is a so-called unchecked exception, because it's a subtype of <code>RuntimeException</code>. 

In java, unchecked exceptions also compile without try-catch

blocks|key|456661|text|NumberFormatException是一个RuntimeException，它未被选中，因此不需要被捕获。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|456662|如果您不知道什么是选中/未选中的Exception是2，请查看文档|456663|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/NumberFormatException.html|1|http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html^0|O|G|0|L|0|0|G|9|Q|1|1|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@$9|U|A|V|1|W]]|E|$]]|$1|F|3|G|5|6|7|X|8|@$9|Y|A|Z|B|C]]|D|@$9|10|A|11|1|12]]|E|$]]|$1|H|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|I|$J|$5|K|L|M|E|$N|O]]|P|$5|K|L|M|E|$N|Q]]]]

<a href="http://docs.oracle.com/javase/1.5.0/docs/api/java/lang/NumberFormatException.html" rel="nofollow">NumberFormatException</a> is a <code>RuntimeException</code> it is unchecked therefore doesn't need to be catched.

Please check the [documentation] if you don't know what a checked/unchecked <code>Exception</code> is<a href="http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html" rel="nofollow">2</a>

blocks|key|4238337|text|据我所知，在java语言中，抛出异常的函数不应该在没有try+|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4238338|+catch的情况下进行编译。|blockquote|4238339|4238340|4238341|对，只需将exception更改为Checked+exception即可。|offset|length|style|CODE|4238342|要对这些有一个清晰的概念，请执行以下操作：|4238343|Effective+Java+Exceptions|4238344|Exceptions|4238345|entityMap|0|LINK|mutability|MUTABLE|url|http://www.oracle.com/technetwork/articles/entarch/effective-exceptions-092345.html|1|http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html^0|0|0|0|0|5|9|H|H|0|0|0|P|0|0|0|A|1|0^^$0|@$1|2|3|4|5|6|7|12|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|13|8|@]|9|@]|A|$]]|$1|E|3|-4|5|6|7|14|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|15|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|16|8|@$I|17|J|18|K|L]|$I|19|J|1A|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|1B|8|@]|9|@]|A|$]]|$1|O|3|P|5|6|7|1C|8|@]|9|@$I|1D|J|1E|1|1F]]|A|$]]|$1|Q|3|R|5|6|7|1G|8|@]|9|@$I|1H|J|1I|1|1J]]|A|$]]|$1|S|3|-4|5|6|7|1K|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]|10|$5|V|W|X|A|$Y|11]]]]

<blockquote>
 As far as I understand in java a function which throws an exception should not be compiled without a try and catch
</blockquote>

Right, just change <code>exception</code> to <code>Checked exception</code>.

Go through following to have a clear idea about these:

<a href="http://www.oracle.com/technetwork/articles/entarch/effective-exceptions-092345.html" rel="nofollow">Effective Java Exceptions</a>

<a href="http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html" rel="nofollow">Exceptions</a>

blocks|key|4238355|text|NumberFormatException是一个RuntimeException。RuntimeExceptions是未检查的异常。您所说的对于受控异常是必需的，但对于未受控异常则不是必需的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4238356|几个链接：|4238357|http://www.javapractices.com/topic/TopicAction.do?Id=129|offset|length|4238358|http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html|4238359|entityMap|0|LINK|mutability|MUTABLE|url|1^0|0|0|0|1K|0|0|0|20|1|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|S|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@$F|U|G|V|1|W]]|A|$]]|$1|H|3|I|5|6|7|X|8|@]|9|@$F|Y|G|Z|1|10]]|A|$]]|$1|J|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|E]]|Q|$5|M|N|O|A|$P|I]]]]

NumberFormatException is a RuntimeException. RuntimeExceptions are unchecked exceptions. What you say is mandatory for checked exception, but not required for unchecked exception.

Couple of link: 
<a href="http://www.javapractices.com/topic/TopicAction.do?Id=129" rel="nofollow">http://www.javapractices.com/topic/TopicAction.do?Id=129</a>
 
<a href="http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html" rel="nofollow">http://docs.oracle.com/javase/tutorial/essential/exceptions/runtime.html</a>

blocks|key|4238374|text|Java中的异常有两种:受控异常和非受控异常。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4238375|检查异常是需要try-catch块或声明的异常。|offset|length|style|CODE|4238376|未检查的异常不需要它。NumberFormatException是一个未检查的异常。|4238377|基本上，未检查的异常派生自RuntimeException，因此不需要声明或try-catch块。|4238378|entityMap^0|0|7|9|0|B|L|0|D|G|12|9|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@$D|P|E|Q|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|J|3|K|5|6|7|U|8|@$D|V|E|W|F|G]|$D|X|E|Y|F|G]]|9|@]|A|$]]|$1|L|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|M|$]]

Exception in Java are of two kinds : checked exceptions and unchecked exceptions.

Checked exceptions are the one which need <code>try-catch</code> block or declaration.

Unchecked exception do not need that. <code>NumberFormatException</code> is an unchecked exception.

Basicaly, unchecked Exception derive from <code>RuntimeException</code>, and thus does not need declaration or <code>try-catch</code> block.

blocks|key|4238409|text|它是一个未检查的exception.The类RuntimeException及其子类是未检查的异常classes.These异常可以发生在code.So中的任何位置捕获该异常并继续执行由您决定|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4238410|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

It is an unchecked exception.The class RuntimeException and its subclasses are unchecked exceptions classes.These exceptions can occur anywhere in your code.So it is upto you to catch that exception and proceed with execution

As far as I understand in java a function which throws an exception should not be compiled without a try and catch or a deceleration in the function above it.
How come then this code is legitimate and dont crush?

<pre><code>public static void main(String[] args) {
 Integer.parseInt("33");
}
</code></pre>

even though Integer.parseInt() 
Throws: NumberFormatException - if the string does not contain a parsable integer.

Why Integer.parseInt is compiling without try catch?

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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据我所知，在java中，抛出异常的函数不应该在上面的函数中没有try和catch或减速的情况下被编译。那么为什么这个代码是合法的，并且不会崩溃呢？public static void main(String[] args) {    Integer.parseInt("33");}即使Integer.parseInt()抛出: NumberFormatException -如果字符串不包含可解析的

问为什么Integer.parseInt在编译时不使用try catch？
EN

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问为什么Integer.parseInt在编译时不使用try catch？EN

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问为什么Integer.parseInt在编译时不使用try catch？
EN