php中运算符表示区间,PHP: 范围解析操作符（::） - Manual

心已赠人 2022-11-12 09:40 129阅读 0赞

This is a solution for those that still need to write code compatible with php 4 but would like to use the flexibility of static variables. PHP 4 does not support static variables within the class scope but it does support them within the scope of class methods. The following is a bit of a workaround to store data in static mode in php 4.

Note: This code also works in PHP 5.

(Tested on version 4.3.1+)

The tricky part is when using when arrays you have to do a bit of fancy coding to get or set individual elements in the array. The example code below should show you the basics of it though.

//You may use and modify this code but please keep this short copyright notice in tact.

//If you modify the code you may comment the changes you make and append your own copyright

//notice to mine. This code is not to be redistributed individually for sale but please use it as part

//of your projects and applications - free or non-free.

//Static workaround for php4 - even works with arrays - the trick is accessing the arrays.

//I used the format s\_varname for my methods that employ this workaround. That keeps it

//similar to working with actual variables as much as possible.

//The s\_ prefix immediately identifies it as a static variable workaround method while

//I'm looking thorugh my code.function &s\_foo($value=null,$remove=null)

static$s\_var;//Declare the static variable.    The name here doesn't matter - only the name of the method matters.if($remove)

if(is\_array($value))

if(is\_array($s\_var))

foreach($valueas$key=>$data)

unset($s\_var\[$key\]);

else

\{//You can't just use unset() here because the static state of the variable will bring back the value next time you call the method.$s\_var=null;

unset($s\_var);

\}//Make sure that you don't set the value over again.$value=null;

if($value)

if(is\_array($value))

if(is\_array($s\_var))

\{//$s\_var = array\_merge($s\_var, $value);        //Doesn't overwrite values. This adds them - a property of the array\_merge() function.foreach($valueas$key=>$data)

\{$s\_var\[$key\] =$data;//Overwrites values.\}

else

\{$s\_var=$value;

else

\{$s\_var=$value;

return$s\_var;

echo"Working with non-array values.  
";

echo"Before Setting: ".StaticSample::s\_foo();

echo"  
";

echo"While Setting: ".StaticSample::s\_foo("VALUE HERE");

echo"  
";

echo"After Setting: ".StaticSample::s\_foo();

echo"  
";

echo"While Removing: ".StaticSample::s\_foo(null,1);

echo"  
";

echo"After Removing: ".StaticSample::s\_foo();

echo"

--------------------

echo"Working with array values  
";$array= array(0=>"cat",1=>"dog",2=>"monkey");

echo"Set an array value: ";print\_r(StaticSample::s\_foo($array));

echo"  
";//Here you need to get all the values in the array then sort through or choose the one(s) you want.$all\_elements=StaticSample::s\_foo();$middle\_element=$all\_elements\[1\];

echo"The middle element: ".$middle\_element;

echo"  
";$changed\_array= array(1=>"big dog",3=>"bat","bird"=>"flamingo");

echo"Changing the value: ";print\_r(StaticSample::s\_foo($changed\_array));

echo"  
";//All you have to do here is create an array with the keys you want to erase in it.

//If you want to erase all keys then don't pass any array to the method.$element\_to\_erase= array(3=>null);

echo"Erasing the fourth element: ";$elements\_left=StaticSample::s\_foo($element\_to\_erase,1);print\_r($elements\_left);

echo"  
";

echo"Enjoy!";?>