Questions about global! Solutions

Questions about global!
I have found that many programs, including Dede, like to declare a global variable in a function, but I have searched the entire site, and I have not seen an externally defined global variable with the same name.

For example, the following example:


function SetVar ($k, $v)
{
Global $_vars;
if (!isset ($_vars[$k]))
{
$_vars[$k] = $v;
}
}

function GetVar ($k)
{
Global $_vars;
return Isset ($_vars[$k])? $_vars[$k]: ";
}

Here $_vars; For the first time in the SetVar function, does it mean that a global variable is defined here, and then the GetVar function below

$_var and $_var in other places are the same global variables?

What's the point of doing this?





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Global if this variable is not present, it will be created as a globals variable.
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is to declare a variable as global, and the entire project remains unique throughout the run!
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It is usually defined on the portal page or on the page where the variable is uniformly defined.

This is a declaration, not a definition. All variables in PHP are likely to be global variables
------Solution--------------------
discuss
I have found that many programs, including Dede, like to declare a global variable in a function, but I have searched the entire site, and I have not seen an externally defined global variable with the same name.

For example, the following example:


function SetVar ($k, $v)
{
Global $_vars;
if (!isset ($_vars[$k]))
{
$_vars[$k] = $v;
}
}

function GetVar ($k ...

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