PHP Array and string offset access syntax with curly braces is deprecated

PHP introduced a deprecation warning in version 7.4.0 about using braces {} to access offsets in arrays and strings. This means that while versions prior to PHP 7.4 may still support this syntax, in PHP 7.4 and later, PHP will issue a deprecation warning when you use braces to access offsets in an array or string. In future versions of PHP (PHP 8.0 and above, this syntax may no longer be supported and may cause runtime errors), this syntax may be completely removed, causing runtime errors.

To follow best practices and ensure code maintainability and future compatibility, it is recommended to use square brackets [] instead of braces {} to access array and string offsets.

For example, the previous code using braces:

$array = array('name' => 'John');  
echo $array{'name'}; // 使用大括号访问数组元素  
  
$string = 'hello';  
echo $string{1}; // 使用大括号访问字符串字符

The code should be updated to use square brackets:

$array = ['name' => 'John'];  
echo $array['name']; // 使用方括号访问数组元素  
  
$string = 'hello';  
echo $string[1]; // 使用方括号访问字符串字符