Why PHP uses references

Why does PHP use quotes

What is a quote?

Quoting in PHP means accessing the same variable content with different names. This is not like a C pointer; instead, the reference is a symbol table alias. Note that in PHP, variable names and variable contents are different, so the same content can have different names. The closest analogy is Unix's filenames and the files themselves - the variable names are the directory entries, and the variable contents are the files themselves. References can be thought of as hardlinks in Unix file systems.

1. Variable reference

2. Function reference transfer

"; echo $b;//输出101 ?>

3. Function Reference return

4. Object reference

abc;//这里输出ABCechob−>abc;//这里输出ABCechoc->abc;//这里输出ABC b−>abc="DEF";echob−>abc="DEF";echoc->abc;//这里输出DEF ?>

5. Reference function

If the program compares If there are many variables that refer to the same object, and you want to clear it manually after using the object, it is recommended to use the "&" method, and then use $var=null to clear it. In other cases, use the default method of php5. In addition, php5 For the transfer of large arrays, it is recommended to use the "&" method, which can save memory space.

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