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Commit 9ae0d7f

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converting-string-to-int-in-java
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‎README.md

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* [如何判断数组Array是否包含指定的值?](https://github.com/giantray/stackoverflow-java-top-qa/blob/master/contents/in-java-whats-the-difference-between-public-default-protected-and-private.md)
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* [重写(Override)equlas和hashCode方法时应考虑的问题](https://github.com/giantray/stackoverflow-java-top-qa/blob/master/contents/what-issues-should-be-considered-when-overriding-equals-and-hashcode-in-java.md)
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* [从一个多层嵌套循环中直接跳出](https://github.com/giantray/stackoverflow-java-top-qa/blob/master/contents/breaking-out-of-nested-loops-in-java.md)
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*[如何将String转换为Int](https://github.com/giantray/stackoverflow-java-top-qa/blob/master/contents/converting-string-to-int-in-java.md)
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> 编程技巧
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- [Generating random integers in a range with Java](http://stackoverflow.com/questions/363681/generating-random-integers-in-a-range-with-java)
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- [Why is printing "B" dramatically slower than printing "#"?](http://stackoverflow.com/questions/21947452/why-is-printing-b-dramatically-slower-than-printing)
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- [What is a serialVersionUID and why should I use it?](http://stackoverflow.com/questions/285793/what-is-a-serialversionuid-and-why-should-i-use-it)
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- [Converting String to int in Java?](http://stackoverflow.com/questions/5585779/converting-string-to-int-in-java)
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- [Is there a unique Android device ID?](http://stackoverflow.com/questions/2785485/is-there-a-unique-android-device-id)
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- [How to test a class that has private methods, fields or inner classes](http://stackoverflow.com/questions/34571/how-to-test-a-class-that-has-private-methods-fields-or-inner-classes)
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- [Why does this code using random strings print "hello world"?](http://stackoverflow.com/questions/15182496/why-does-this-code-using-random-strings-print-hello-world)
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##如何将String转换为Int
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有两种方式
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```java
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Integer x = Integer.valueOf(str);
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// or
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int y = Integer.parseInt(str);
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```
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这两种方式有一点点不同:
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- `valueOf`返回的是`java.lang.Integer`的实例
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- `parseInt`返回的是基本数据类型 int
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`Short.valueOf/parseShort`,`Long.valueOf/parseLong`等也是有类似差别。
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另外还需注意的是,在做int类型转换时,可能会抛出NumberFormatException,因此要做好异常捕获
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```java
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int foo;
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String StringThatCouldBeANumberOrNot = "26263Hello"; //will throw exception
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String StringThatCouldBeANumberOrNot2 = "26263"; //will not throw exception
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try {
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foo = Integer.parseInt(StringThatCouldBeANumberOrNot);
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} catch (NumberFormatException e) {
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//Will Throw exception!
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//do something! anything to handle the exception.
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}
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try {
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foo = Integer.parseInt(StringThatCouldBeANumberOrNot2);
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} catch (NumberFormatException e) {
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//No problem this time but still it is good practice to care about exceptions.
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//Never trust user input :)
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//do something! anything to handle the exception.
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}
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```
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stackoverflow链接:http://stackoverflow.com/questions/5585779/converting-string-to-int-in-java

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