Php function variable scope and function return value tutorial

Php function variable scope and function return value tutorial in php about variables defined in a function, including parameters, cannot access function external variables, and by default, function variables that cannot be accessed by variables defined outside a function.

The code is as follows:

$ A = 1;

$ B = 2;

Function Sum ()

{

Global $ a, $ B;

$ B = $ a + $ B;

}

Sum ();

Echo $ B;

?>

In this way, the value of $ B is 3, and global is a global variable in php. the code is as follows:

Function str_unite (& $ string)

{

$ String. = 'also like blue .';

}

$ Str = 'like red ,';

Str_unite ($ str );

Echo $ str; // output result: 'Like red or blue .'

?>

The above is about the global variables of the function scope and the reference of the function. the code is as follows:

$ A = 1;

$ B = 2;

Function Sum ($ a, $ B)

{// Open source code phpfensi.com

$ B = $ a + $ B;

Echo $ B; // 3

}

Sum ();//

Echo $ B; // 2

?>