unset function

Use the previous example:PHP codeCopy codeThe Code is as follows:// Example 1Function test_global (){Global $ var1, $ var2;$ Var2 = & $ var1;}Function test_globals (){$ GLOBALS ['var3'] = & $ GLOBALS ['var1'];}$ Var1 = 5;$ Var2 = $ var3 =

This may cause some problems. Some may carelessly change a global variable. Global variables in PHP must be declared as Global when used in functions (note that the Global keyword is useful in function definition ).1: Global is used to define Global

The function of the PHPsession variable is to store the user's session information or change the user's session settings. The Session variable stores the information of a single user, which can be used by all pages. PHPSession variable when you run

1) Why is the result of $ a hello instead of undefined? {Code...} 2) Why is the result of $ a 1 instead of 2? {Code...} 1) Why is the $ a result hello instead of undefined? $a = "hello";$b =& $a;unset($b);$b = "world";var_dump($a); // hello 2) Why

The unset () function of PHP is used to clear and destroy variables. unused variables can be destroyed using unset. However, in some cases, the memory occupied by destroying variables cannot be reached with unset! Copy codeThe code is as

Difference between global and $ GLOBALS in php. Some friends say that these two are actually differences in writing. let me prove the difference between global and $ GLOBALS. if you need them, please refer to them for details. According to the

Arrays in PHP are actually an ordered ING. Valuing is a type that associates values with keys. This type has been optimized in many ways, so it can be treated as a real array, or a list (vector), a scattered list

The most comprehensive php memory overflow solution 1. memory overflow solution During data statistical analysis, large arrays are often encountered, and memory overflow may occur. here is my solution. The problem is illustrated in the following

The deletion of the array elements in PHP is very simple, mainly unset,array_splice, but about the two have, for a long time mixed, sometimes even the difference. A lot of places are so different unset,array_splice If the Array_splice () function

Arrays in PHP are actually an ordered ING. Valuing is a type that associates values with keys. This type has been optimized in many aspects, so it can be treated as a real array, or a list (vector), a hash list (an implementation of ing ), the array

This article mainly introduces PHP three ways to clear the session, interested in the friend's reference, I hope to help you. Session Delete Clear is very fastidious if we can clear the specified variable if we are not careful to remove all the

There are many ways to delete sessions in php. This article mainly introduces three methods for clearing sessions, if you are interested, follow the editor to learn how to delete and clear sessions. If we have defined the settings, we can clear the

The unset function is a function of PHP's own destruction variables, we introduced the use of unset to destroy the static variables and global variables, and can destroy the array variable Oh, let's look at the example below. Example 1. Unset ()

An interesting question about php Destructor with the popularity of object-oriented programming, object-oriented shows many interesting questions. I believe many beginners will come into contact with two functions, constructor and Destructor, when

One of the biggest benefits of using scripting languages is the automatic garbage collection mechanism (which frees up memory) that it has. You do not need to do any free memory processing after using the variables, PHP will help you to complete.Of

Get Started with PHP (String, cookie,session), a friend of the need can refer to below. StringGets the length of the string: strlen () functionGet Chinese text long echo mb_strlen ($str, "UTF8");English string interception $str = '

In PHP, the analysis of global and $ GLOBALS [] in php is not just a different way of writing, but the difference between global and $ GLOBALS is still very big. pay attention to it in practical application! Let's take a look at the following

PHP references ??? The so-called PHP reference is a different name that accesses the same variable content. Can be used on variables, functions, and objects, with the use of a & symbol in front of them. The following are the types and effects of

Opposite to Constructor, in PHP5, you can define a function named _ destruct (), called PHP5 destructor, PHP will call the destructor before the object is destroyed in the memory, so that the object can complete some work before it completely

In PHP, the analysis of global and $ GLOBALS [] in php is not just a different way of writing, but the difference between global and $ GLOBALS is still very big. pay attention to it in practical application! Let's take a look at the following