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rurtubia/variable_scope.php

Last active November 5, 2015 22:37
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PHP Variables
Raw
variable_scope.php
<!DOCTYPE HTML>
<HTML>
<BODY>
<?php
//GLOBAL VARIABLES are written outside any functions and can only be accessed outside functions
$vg1 = 123;
$vg2 = 456;
echo $vg1 + $vg2;
//LOCAL VARIABLES exist only inside a function:
function testFuncion(){
$vl1 = 123;
$vl2 = 444;
echo $vl1 + $vl2;
}
//Calling the function:
testFunction();
//USING A GLOBAL VARIABLE FROM A LOCAL CONTEXT
function testFuncion2(){
$vl1 = 123;
# it's necessary to call the variable before using it.
global $vg1;
# after that it can be used.
echo $vg1 + $vl1;
}
testFunction2();
//GLOBAL VARIABLES ARE STORED IN AN ARRAY CALLED $GLOBALS
#and they can be used and modified from within a local context
function testFunction3(){
$GLOBALS['vg1'] = $GLOBALS['vg1'] + $GLOBALS['vg2'];
}
testFunction3();
#prints the new value of vg1
echo "<br>";
echo $vg1;
?>
</BODY>
</HTML>
Raw
variables.php
<!DOCTYPE HTML>
<HTML>
<BODY>
<?php
#php variables start with the $ symbol and then have a name
$var1 = "variable";
#the variable name cannot start with a number
#a variable name can only contain A-z, 0-9 and _
#variable names are case sensitive
//VARIABLE OUTPUT
#to output a variable, we use the echo comand
echo "this is a $var1!";
#we can use the concatenation operator "."
echo "this is a " . $var1 . "!";
#Math operations with variables:
echo "<br>";
echo "The sum of 10 + 50 is ";
echo $x + $y;
?>
</BODY>
</HTML>
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