On the Internet saw that the difference written only in writing, is it?

from the bottom of his friend Saidolim wrote one example, I want to continue the question …

there is such a code

/// Example 1
$ STR = "SIMPLE TEXT";
$ A = FUNCTION ()
{
  Global $ str;
  $ str = "edited";
};
$ a ();
Echo $ str. "\ n"; /// edited
/// Example 2.
$ STR = "SIMPLE TEXT";
$ A = FUNCTION ()
{
  $ Globals ["Str"] = "edited";
};
$ a ();
Echo $ str. "\ n"; /// edited
/// Example 3.
$ STR = "SIMPLE TEXT";
$ temp = "";
$ A = FUNCTION ()
{
  $ Globals ["Temp"] = & amp; $ globals ["str"];
};
$ a ();
Echo "[". $ str. "] [". $ temp. "] \ n"; /// [SIMPLE TEXT] [Simple Text]
/// Example 4.
$ STR = "SIMPLE TEXT";
$ temp = "";
$ A = FUNCTION ()
{
  Global $ str, $ temp;
  $ temp = & amp; $ str;
};
$ a ();
Echo "[". $ str. "] [". $ temp. "] \ n"; /// [SIMPLE TEXT] []

The first example displays as expected modified value, the second example is the same … It would seem difference no, go further! In the third example, in the function, we make a tough reference for the elements of a superglobal array displays as expected one and the same word, and now we look at the fourth example and … I don’t line in a stupor and displays only the variable $ str , and the variable $ Temp leaves empty, why?

p.s wrote here because I did not want to spam questions on the same

Answer 1, Authority 100%

Instructions Global addresses the Global array $ globals . And gets the value of the variable $ globals ['var'] . The difference is only in writing.

p.s. Tip when using global variables: stay away from them, using them only when you can’t do without them.

Abuse of global variables can bring a person analyzing your code to white hot.

Answer 2, Authority 50%

Let’s turn to the documentation (this is, by the way, it is very useful to do)

$ globals – links to all variables of the global area of ​​visibility

This ‘superglobal’ or automatic global variable. it
Simply means that it is available in all contexts of the script. No
need to perform Global $ Variable; To access her inside
method or functions.

In fact, they provide access to the same objects. Difference only in the method of use.

And how correctly noted @firepro, the use of global either $ globals is very bad.

Answer 3, Authority 50%

1. Global I think it works faster. Since the approach is different. But when you use a variable, it is difficult for you to understand it global or not.
2. $ globals more readable and easy to understand. Since it is obvious that the global variable.
3. if you want to use unset global variable, you must use unset ($ globals ['varname']) , and not global $ varname; Unset ($ Varname); .

I think more detail. You can learn here

UPD

To compare these commands. I propose to check the following code:

function test_global () {
 Global $ var1, $ var2;
 $ var2 = & amp; $ var1;
}
Function Test_Globals () {
 $ Globals ['Var3'] = & amp; $ Globals ['Var1'];
}
$ var1 = 5;
$ var2 = 0;
$ var3 = 0;
test_global ();
Print $ var1. "& GT;". $ var2. "";
Echo "& lt; br / & gt;";
test_globals ();
Print $ var1. "& GT;". $ var3;

result

5 & gt; 0.
5 & ​​gt; 5

But I would advise you to use the following scheme when you work with variables:

function MyFunc (& amp; $ MyVar)
{
  $ MyVar = 10;
} 
$ foo = 0;
myFunc ($ foo);
var_dump ($ foo); // result 10

Here, as you can see, the variable is passed to the function as a reference, and the function has the right to change its value. And Inside the function it is easier to understand that someone gave you a variable and you change its value.

It is better to bypass globality than to use it.

Answer 4, authority 25%

There is actually a difference between the $ GLOBALS superglobal variable and the global keyword in php.

The point is that $ GLOBALS refers to a variable directly, while global injects a variable from the global scope (and, as far as I can tell , only from it) to the corresponding local scope.

The documentation is about this, but only in passing … The situation is similar for Zend Engine 2 and phpng.