Analysis of calling methods referenced by PHP_php skills

The example in this article describes the calling method of PHP reference. Share it with everyone for your reference, the details are as follows:

Example 1:

function test($arr){} 
echo test(&$arr); 

Example 2:

function test(&$arr){} 
echo test($arr); 

Examples 1 and 2 have the same effect.

Example 3:

function &test($arr){return $result;} 
echo &test($a);//有效 
echo test($a);//返回的是值,不是引用 

Summary: References are returned only when & is added before the method name when defining a method and & is added before the method name when calling a method.

Example 4:

$a=$b; 

When neither $a nor $b is reassigned, that is, when no writing operation occurs, it is the same as $a=&$b, which is equivalent to assigning a reference.

Only when $a or $b changes, a copy of the value will be assigned to $a

I hope this article will be helpful to everyone in PHP programming.