Detailed explanation of naming rules for variables in php

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In fact, it would be better to have some naming rules, otherwise it will be ugly without statistics. Here is a detailed explanation of PHP variable naming rules. I hope the following article will be useful to you.

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PHP variable naming rules

1. Variables start with the dollar sign $. Such as $name, $age.

2. The first character after the dollar sign $ cannot be a number, but can only be an underscore_ or a letter. Variables like $1_1 are wrong.

3. Except for underscore_, no spaces or punctuation marks are allowed in variables. That is to say, the variable name can only contain: a-z, A-Z, 0-9 and underscore_.

4. PHP variable names are case-sensitive. For example, $name and $Name are two different variables.

PHP Variable Naming Rules Other Notes

1. When naming a variable with two or more words, you can use Capitalize the first letter of all words. Such as $myName, $yourFamilyName.

2. Variables named starting with underscore _ usually represent special variables. Such as creating protected attributes, PHP predefined variables ($_GET), global arrays, etc. in the class.

3. When defining variables, do not be greedy for brevity. Instead, use descriptive names to define variables.

Learning without thinking is useless, thinking without learning is dangerous. I hope you have smooth sailing on your journey to learn PHP and become a master of the art of PHP programming.
The above is the entire content of PHP variable naming rules. The following is nonsense, if you have time, you might as well read it briefly, maybe you can relate.

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PHP variable naming rules

From college to now, I have been exposed to various programming languages. Such as client-side languages ​​Javascript, Actionscript; server-side languages ​​C, Java, ASP.net, PHP, etc., to name a few. Of all these languages, the one I want to learn the most is PHP. For no other reason than the pronunciation of PHP: fart H fart, which is catchy and full of charm. Today I saw the section on PHP variable naming rules, so I just wrote something casually to pass the boring time.

The learning of PHP has been intermittent. The ambition to learn PHP well when I was young is almost gone now.

Some people say that no one can live spotlessly in such a society. What kind of society is this? I am not very sure. But I heard people say that this is an era where the deaf hear the dumb and say that the blind have seen love. I don’t completely believe it, but I can’t completely disbelieve it either.

No matter what, since living is not easy, then live and cherish it.

PHP is something I want to cherish.

So, today I checked out a new book borrowed from the library - PHP Dynamic Web Design (Second Edition, author David Powers).

See the PHP variable naming rules section. Reviewing these very basic contents after a few years really feels like reviewing the past and learning something new.

In order to make the impression more profound, and to practice the truth that a good memory is not as good as a bad writing, in this restless night, I decided to write this article, dedicated to myself who once wanted to be a PHP master. .

1. Variables start with the dollar sign $. Such as $name, $age;

2. The first character after the dollar sign $ cannot be a number;

3. Except for the underscore _, no spaces or punctuation are allowed in variables. Symbol;

4. PHP variable names are case-sensitive. For example, $name and $Name are two different variables.

Other notes

1. When naming a variable with two or more words, you can capitalize the first letter of all words except the first word. For example, $myName; $yourFamilyName;

2. Variables named starting with underscore _ are usually reserved for special situations. For example, create protected attributes in classes; PHP predefined variables: global arrays, etc.;

3. When defining variables, do not be greedy for brevity, but use descriptive names to define variables.

Example

The following are the same function named using camel notation and underscore method respectively:

printEmployeePaychecks()；
print_employee_paychecks()；

第一个函数名使用了骆驼式命名法——函数名中的每一个逻辑断点都有一个大写字母来标记；第二个函数名使用了下划线法----函数名中的每一个逻辑断点都有一个下划线来标记。
骆驼式命名法近年来越来越流行了，在许多新的函数库和Microsoft　Windows这样的环境中，它使用得相当多。另一方面，下划线法是c出现后开始流行起来的，在许多旧的程序和UNIX这样的环境中，它的使用非常普遍。

编辑本段应用概述

骆驼式命名法（Camel-Case）是电脑程式编写时的一套命名规则（惯例）。

骆驼式命名法就是当变量名或函式名是由一个或多个单字连结在一起，而构成的唯一识别字时，第一个单词以小写字母开始；第二个单词的首字母大写或每一个单词的首字母都采用大写字母，例如：myFirstName、myLastName，这样的变量名看上去就像骆驼峰一样此起彼伏，故得名。

骆驼式命名法（Camel-Case）一词来自 Perl 语言中普遍使用的大小写混合格式，而 Larry Wall 等人所著的畅销书《Programming Perl》（O'Reilly 出版）的封面图片正是一匹骆驼。
骆驼式命名法的命名规则可视为一种惯例，并无绝对与强制，为的是增加识别和可读性。

驼峰法（小驼峰法）

变量一般用小驼峰法标识。驼峰法的意思是：除第一个单词之外，其他单词首字母大写。譬如

int myStudentCount;

变量myStudentCount第一个单词是全部小写，后面的单词首字母大写。

Pascal法（大驼峰法）

相比小驼峰法，大驼峰法把第一个单词的首字母也大写了。常用于类名，函数名，属性，命名空间。譬如

publicclass DataBaseUser;

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