---
title: Basic Syntax
localeTitle: 基本语法
---
# 基本语法

PHP脚本可以放在文档中的任何位置。

PHP脚本以`<?php`开头，以`?>`结尾

下面，我们有一个简单的PHP文件示例，其中一个PHP脚本使用内置的PHP函数“echo”来输出文本“Hello World！”。在网页上

\`\`\`\`

# 我的第一个PHP页面
```
The output of that would be : 
```

我的第一个PHP页面

你好，世界！
```
#### Note: PHP statements end with a semicolon (;). 
 
 # Comments in PHP 
 
 PHP supports several ways of commenting: 
```

```
# PHP Case Sensitivity 
 
 In PHP, all keywords (eg if, else, while, echo, etc.), classes, functions, and user-defined functions are NOT case-sensitive. 
 
 In the example below, all three echo statements below are legal (and equal): 
```

```
### However; all variable names are case-sensitive. 
 
 In the example below, only the first statement will display the value of the $color variable (this is because $color, $COLOR, and $coLOR are treated as three different variables): 
```

\`\`\`\`