Java 为什么要在变量名前加_（下划线）？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/20677249/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Why we add _ (underscore) before variable name?
提问by
I know this can be silly question but I actually don't know that why we add _ (underscore) before variable name in java while Variable declaration.
我知道这可能是一个愚蠢的问题，但我实际上不知道为什么我们在变量声明时在 java 中的变量名之前添加 _ （下划线）。
I have tried on google but I actually can't find exact answer of it. So anyone tell me is it just a type of declaration as user want or is there any proper mechanism and reason to do so.
我试过谷歌，但实际上我找不到确切的答案。所以有人告诉我这只是用户想要的一种声明，还是有任何适当的机制和理由这样做。
Thank You In Advance.
先感谢您。
回答by Liping Huang
this should be an idiomatic usage.
这应该是惯用的用法。
回答by Maroun
Sometimes it is used in order to distinguish class membersfrom local variables:
有时它用于区分类成员和局部变量：
public class MyClass {
private int _salary;
public MyClass(int salary) {
_salary = salary
}
}
However, you should follow Java Naming Conventionsthat doesn't recommend using that. You can simply name the class member without the leading _and do:
但是，您应该遵循不推荐使用它的Java 命名约定。您可以简单地命名没有前导的类成员_并执行以下操作：
this.salary = salary;
回答by Dennis Traub
An underscore in front usually indicates a instance variable as opposed to a local variable. It's merely a coding style that can be omitted in favor of "speaking" variable names and small classes that don't do too many things.
前面的下划线通常表示实例变量而不是局部变量。它只是一种可以省略的编码风格，有利于“说出”变量名和不做太多事情的小类。
回答by Francesco Irrera
The use of " _ " (underscore) must be evaluated carefully.
Use " _ " to indicate class attributes is used a lot in C + +.
In Java, it is not necessary because the language has the keyword this.
必须仔细评估“_”（下划线）的使用。
用“_”表示类属性在C++中使用较多。在 Java 中，没有必要，因为该语言具有关键字this。
