PHP 关键字“var”有什么作用？
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What does PHP keyword 'var' do?
提问by joelpet
This is probably a very trivial question, but I haven't been able to find the answer neither through web search engines, nor on php.net. Please just direct me to where I can read about this, if you haven't got time to explain.
这可能是一个非常微不足道的问题，但我无法通过网络搜索引擎或 php.net 找到答案。如果您没有时间解释，请直接将我指向我可以阅读的地方。
- What does the 'var' keyword mean in PHP?
- Are there any differences between PHP4 and PHP5?
- PHP 中的“var”关键字是什么意思？
- PHP4 和 PHP5 之间有什么区别吗？
采纳答案by karim79
It's for declaring class member variables in PHP4, and is no longer needed. It will work in PHP5, but will raise an E_STRICTwarning in PHP from version 5.0.0 up to version 5.1.2, as of when it was deprecated. Since PHP 5.3, var has been un-deprecated and is a synonym for 'public'.
它用于在 PHP4 中声明类成员变量，不再需要。它可以在 PHP5 中工作，但会E_STRICT在 PHP 5.0.0 到 5.1.2 版本中引发警告，因为它被弃用了。自 PHP 5.3 起，var 不再被弃用，它是“public”的同义词。
Example usage:
用法示例：
class foo {
var $x = 'y'; // or you can use public like...
public $x = 'y'; //this is also a class member variables.
function bar() {
}
}
回答by Gumbo
The varkeyword is used to declare variables in a class in PHP 4:
该var关键字用于在 PHP 4 中声明类中的变量：
class Foo {
var $bar;
}
With PHP 5 property and method visibility(public, protectedand private) was introduced and thus varis deprecated.
在 PHP 5中引入了属性和方法可见性（public,protected和private），因此var不推荐使用。
回答by taatparya
I quote from http://www.php.net/manual/en/language.oop5.visibility.php
我引用自http://www.php.net/manual/en/language.oop5.visibility.php
Note: The PHP 4 method of declaring a variable with the var keyword is still supported for compatibility reasons (as a synonym for the public keyword). In PHP 5 before 5.1.3, its usage would generate an
E_STRICTwarning.
注意：出于兼容性原因（作为 public 关键字的同义词），仍然支持 PHP 4 使用 var 关键字声明变量的方法。在 PHP 5 5.1.3 之前，它的使用会产生
E_STRICT警告。
回答by Webeng
Answer:From php5.3 and >, the varkeyword is equivalent to publicwhen declaring variables inside a class.
答：从php5.3 and 开始>，var关键字相当于public在类中声明变量时。
class myClass {
var $x;
}
is the same as (for php5.3 and >):
与（对于php5.3 和>）相同：
class myClass {
public $x;
}
History:It was previously the norm for declaring variables in classes, though later became depreciated, but later (PHP 5.3) it became un-depreciated.
历史：以前是在类中声明变量的规范，虽然后来贬值了，但后来（PHP 5.3）它变得不贬值了。
回答by kta
So basically it is an old style and do not use it for newer version of PHP. Better to use Public keyword instead;if you are not in love with var keyword. So instead of using
所以基本上它是一种旧样式，不要将它用于较新版本的 PHP。最好改用 Public 关键字；如果您不喜欢 var 关键字。所以而不是使用
class Test {
var $name;
}
Use
用
class Test {
public $name;
}
回答by xayer
In PHP7.3 still working...
在 PHP7.3 中仍然有效...
https://www.php.net/manual/en/language.oop5.visibility.php
https://www.php.net/manual/en/language.oop5.visibility.php
If declared using var, the property will be defined as public.
如果使用 var 声明，则该属性将定义为 public。
回答by kumar
var is used like public .if a varable is declared like this in a class var $a; if means its scope is public for the class. in simplea words var ~public
var 像 public 一样使用。如果一个变量在类 var $a 中是这样声明的；if 表示它的范围是该类的公共范围。简单来说 var ~public
var $a;
public
回答by NappingRabbit
here and now in 2018using varfor variable declaration is synonymous with publicas in
这里和现在2018使用var的变量声明是同义的public，如
class Sample{
var $usingVar;
public $usingPublic;
function .....
}
