PHP Basic 02: Variables

1. Create a variable

<? PHP     $num 1 =;     $num 2 = 15.5;     Echo $num 1+$num 2;     Echo "<br>";? >

2.Local and Global Scopes

<?PHP$x= 5;//Global    functionmyTest () {$y= 10;//Local        Echo"X:$x"; Echo"<br>"; Echo"Y:$y"; Echo"<br>";    } myTest (); Echo"; Echo"X:$x"; Echo"<br>"; Echo"Y:$y";?>

3.PHP Global Keywords

<? PHP     $c = ten;     $d =;     function Test () {        global$c$d$f;         $f $c $d ;    }    Test ();     Echo "$f";? >

4.PHP also stores all global variables in an array named $GLOBALS [index]. The subscript contains the variable name. This array is also accessible within the function and can be used to update global variables directly.

<? PHP     $x = 5;     $y =;     function test4 () {        $GLOBALS$GLOBALS$GLOBALS[' x '];    }    Test4 ();     Echo "$y";? >

5.PHP Static Keywords

Typically, all variables are deleted when the function finishes/executes. However, sometimes I need to not delete a local variable. Achieving this requires a bit of further work. To do this, use the static keyword when you first declare a variable:

<? PHP     function myTest () {          static$x=0;           Echo $x ;           $x+ +;    }    MyTest ();    MyTest ();    MyTest ();? >

PHP Basic 02: Variables