PHP Conditional Expression Evaluation With TRUE and FALSE

PHP Conditional Expression Evaluation With TRUE and FALSE
Conditional expressions (both if and while statements) are literal or boolean or numeric.
Numeric expressions evaluate to true when they are non-zero – zero/0 is false.
String expressions evaluate to TRUE when there is nonempty string.  A NULL value is evaluated as
false.
How do you assign a NULL to a string or any other type of variable?
$s_var = NULL;  // or just set it to false – that  is null too
This little code snippet demonstrates the value of TRUE and FALSE ( 1 and NULL ), with strings and numbers

<?php
 echo 'We are setting $hungry to true <br>';
$hungry=TRUE;
 print 'The value of the $hungry variable is: '.$hungry;
 echo "<br>";
 echo $hungry ? "Lets eat now" : "Not hungry yet";
 echo '<br>We are setting $hungry to false<br>';
 $hungry=FALSE;
if ($hungry) {
 echo "Now food please";
 }
 else
 {
 echo "Can we eat later?";
 }
 echo "<br>";
 print "The value of the \$hungry variable is $hungry";
 print "<br> So what were are saying is TRUE = 1 and FALSE=NULL ";
echo "<br> Now lets set the var to NULL and see that it also matches FALSE <br>";
 $hungry=NULL;
if ($hungry) {
 echo "Now food please";
 }
 else
 {
 echo "Can we eat later?";
 }
echo "<br>";
 echo 'now lets change $hungry\'s data type to number, remembering any numeric value including 0/zero will evaluate to true';
 echo "<br>";
 $hungry = 0;
 if ($hungry) {
 echo "Now food please";
 }
 else
 {
 echo "Can we eat later?";
 }
 echo "<br>";
 echo "<br>";
 echo 'now lets change $hungry\'s data type to string';
 echo "<br>";
 $hungry = "famished";
 if ($hungry) {
 echo "Now food please";
 }
 else
 {
 echo "Can we eat later?";
 }
 ?>

We are setting $hungry to true
The value of the $hungry variable is: 1
Lets eat now
We are setting $hungry to false
Can we eat later?
The value of the $hungry variable is
So what were are saying is TRUE = 1 and FALSE=NULL
Now lets set the var to NULL and see that it also matches FALSE
Can we eat later?
now lets change $hungry’s data type to number, remembering any numeric value except 0/zero will evaluate to true
Now food please
now lets change $hungry’s data type to string
Now food please

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