blocks|key|3068404|text|静态方法的一种常见用法是在命名构造函数习惯用法中。请参阅：http://www.parashift.com/c%2B%2B-faq-lite/ctors.html#faq-10.8|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3068405|entityMap|0|LINK|mutability|MUTABLE|url|http://www.parashift.com/c%2B%2B-faq-lite/ctors.html#faq-10.8^0|T|1L|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

One common usage of static methods is in the named constructor idiom. See: <a href="http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.8" rel="nofollow noreferrer">http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.8</a>.

blocks|key|319668|text|您对静态变量的描述更适合于C中的描述。面向对象术语中的静态变量的概念在概念上是不同的。我在这里借鉴了Java的经验。当静态方法和字段在概念上不属于某物的实例时，它们很有用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|319669|考虑一个Math类，它包含一些常见的值，如Pi或e，以及一些有用的函数，如sin和cos。创建单独的实例来使用这种功能真的没有意义，因此它们作为静态功能更好：|319670|//+This+makes+little+sense
Math+m+=+new+Math();
float+answer+=+m.sin(45);

//+This+would+make+more+sense
float+answer+=+Math.sin(45);|code-block|syntax|javascript|319671|在OO语言中(同样，从Java的角度来看)，函数，或者更广为人知的方法，不能有静态局部变量。只有类才能有静态成员，正如我所说的，这与C中的静态概念几乎没有什么相似之处。|319672|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Your description of a static variable is more fitting to that found in C. The concept of a static variable in Object Oriented terms is conceptually different. I'm drawing from Java experience here. Static methods and fields are useful when they conceptually don't belong to an instance of something. 

Consider a Math class that contains some common values like Pi or e, and some useful functions like sin and cos. It really does not make sense to create separate instances to use this kind of functionality, thus they are better as statics:

<pre><code>// This makes little sense
Math m = new Math();
float answer = m.sin(45);

// This would make more sense
float answer = Math.sin(45);
</code></pre>

In OO languages (again, from a Java perspective) functions, or better known as methods, cannot have static local variables. Only classes can have static members, which as I've said, resemble little compared to the idea of static in C.

blocks|key|3281503|text|只有当给定的方法不需要创建类的实例时，才需要在类中使用静态方法。这可能是在试图返回共享数据源(例如单例)或执行不修改对象内部状态的操作(例如String.format)时发生的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3281504|维基百科的这篇词条很好地解释了静态方法：http://en.wikipedia.org/wiki/Method_(computer_science)#Static_methods|offset|length|3281505|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Method_(computer_science)#Static_methods^0|0|K|1X|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@$D|P|E|Q|1|R]]|A|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|M]]]]

The only time you want to use a static method in a class is when a given method does not require an instance of a class to be created. This could be when trying to return a shared data source (eg a Singleton) or performing an operation that doesn't modify the internal state of the object (String.format for example).

This wikipedia entry explains static methods pretty well: <a href="http://en.wikipedia.org/wiki/Method_(computer_science)#Static_methods" rel="noreferrer">http://en.wikipedia.org/wiki/Method_(computer_science)#Static_methods</a>

blocks|key|3281528|text|静态变量和静态方法绑定到类，而不是类的实例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3281529|静态方法不应该包含"state“。任何与状态相关的东西都应该绑定到实例化的对象，而不是类。|3281530|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Static variables and static methods are bound to the class, and not an instance of the class.

Static methods should not contain a "state". Anything related to a state, should be bound to an instantiated object, and not the class.

blocks|key|3068449|text|从本质上讲，静态方法允许您用面向对象的语言编写过程代码。它允许您调用方法，而不必先创建对象。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068450|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|$]]

Essentially, static methods let you write procedural code in an object oriented language. It lets you call methods without having to create an object first.

blocks|key|3068452|text|Static+Methods+in+PHP|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3068453|可以在不创建类对象的情况下调用。|3068454|只能调用静态方法和函数。|3068455|entityMap|0|LINK|mutability|MUTABLE|url|http://www.victorchen.info/how-to-create-php-static-method/^0|0|L|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]]|C|$]]|$1|D|3|E|5|6|7|T|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|U|8|@]|9|@]|C|$]]|$1|H|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|I|$J|$5|K|L|M|C|$N|O]]]]

<a href="http://www.victorchen.info/how-to-create-php-static-method/" rel="nofollow noreferrer">Static Methods in PHP</a>:

Can be called without creating a class object.

Can only call on static methods and function.

blocks|key|322715|text|静态方法不会将"this“指针传递给对象，因此它们不能引用非静态变量或方法，但在运行时可能会更有效(参数更少，创建和销毁对象没有开销)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|322716|它们可用于将内聚方法分组到单个类中，或作用于其类的对象，例如在工厂模式中。|322717|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Static methods don't pass a "this" pointer to an object, so they can't reference non-static variables or methods, but may consequently be more efficient at runtime (fewer parameters and no overhead to create and destroy an object).

They can be used to group cohesive methods into a single class, or to act upon objects of their class, such as in the factory pattern.

blocks|key|3281585|text|静态方法的语法(php)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3281586|<?php
class+Number+{
++++public+static+function+multiply($a,+$b)+{
++++++++return+$a+*+$b;
++++}
}
?>|code-block|syntax|javascript|3281587|客户端代码：|3281588|echo+Number::multiply(1,+2);|3281589|这比以下内容更有意义：|3281590|$number+=+new+Number();
echo+$number->multiply(1,+2);|3281591|因为multiply()方法不使用任何类变量，因此不需要Number的实例。|offset|length|style|CODE|3281592|entityMap^0|0|0|0|0|0|0|2|A|S|6|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|11|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|12|8|@$Q|13|R|14|S|T]|$Q|15|R|16|S|T]]|9|@]|A|$]]|$1|U|3|-4|5|6|7|17|8|@]|9|@]|A|$]]]|V|$]]

Syntax (php) for static methods:

<pre><code>&lt;?php
class Number {
 public static function multiply($a, $b) {
 return $a * $b;
 }
}
?&gt;
</code></pre>

Client code:

<pre><code>echo Number::multiply(1, 2);
</code></pre>

Which makes more sense than:

<pre><code>$number = new Number();
echo $number-&gt;multiply(1, 2);
</code></pre>

As the <code>multiply()</code> method does not use any class variables and as such does not require an instance of <code>Number</code>.

blocks|key|3281622|text|当你想在class.As变量的不同对象之间共享一些信息时，可以使用静态变量，每个对象都可以更新它，更新后的值也可以用于所有其他对象。因为静态变量可以共享，所以它们通常被称为类变量。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3281623|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|$]]

Static variable is used when you want to share some info between different objects of the class.As variable is shared each object can update it and the updated value be available for all other objects as well.
As static variable can be shared,these are often called as class variable.

blocks|key|3068585|text|静态元素可以从任何上下文(即脚本中的任何位置)访问，因此您可以访问这些方法，而无需将类的实例从一个对象传递到另一个对象。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3068586|静态元素在类的每个实例中都可用，因此您可以设置希望对某个类型的所有成员可用的值。|3068587|为了进一步阅读a+link！|offset|length|3068588|entityMap|0|LINK|mutability|MUTABLE|url|http://phpduck.com/php-static-methods-and-properties/^0|0|0|7|6|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|R|8|@]|9|@$F|S|G|T|1|U]]|A|$]]|$1|H|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|O]]]]

static elements are accessible from any context (i.e. anywhere in your script), so you can access these methods without needing to pass an instance of the class from object to object.

Static elements are available in every instance of a class, so you can set values that you want to be available to all members of a type.

for further reading <a href="http://phpduck.com/php-static-methods-and-properties/" rel="nofollow">a link</a>!

I have concept of static variables but what are the benefits of static methods in a class. I have worked on some projects but I did not make a method static. Whenever I need to call a method of a class, I create an object of that class and call the desired method. 

Q: Static variable in a method holds it's value even when method is executed but accessible only in its containing method but what is the best definition of static method? 

Q: Is calling the static method without creating object of that class is the only benefit of static method? 

Q: What is the accessible range for static method? 

Thanks

When should I use static methods in a class and what are the benefits?

Java

我有静态变量的概念，但是在类中使用静态方法有什么好处呢？我曾经在一些项目中工作过，但我没有创建静态的方法。每当我需要调用类的方法时，我都会创建该类的对象并调用所需的方法。Q:方法中的静态变量即使在方法执行时也会保持它的值，但只能在其包含的方法中访问，但是静态方法的最佳定义是什么？Q:调用静态方法而不创建类的对象是静态方...

问我应该在什么时候在类中使用静态方法，有什么好处？
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