Logical operators are used when we want to combine operations and
expressions into a set of logical comparisons. They are usually used in
conjuction with "if and "else" statements to lay out the dynamic logic
we need in many situations as we advance in our PHP development. We
discuss if and else statements in later lessons.
The following table shows their usage and result logic:
| Name |
Usage |
Result |
| And |
$var1 &&
$var2 |
TRUE if both $var1 and $var2
are TRUE |
| And |
$var1 and $var2 |
TRUE if both $var1 and $var2
are TRUE |
| Or |
$var1 or $var2 |
TRUE if either $var1 or
$var2 is TRUE |
| Or |
$var1 || $var2 |
TRUE if either $var1 or
$var2 is TRUE |
| Xor |
$var1 xor $var2 |
TRUE if either $var1 or
$var2 is TRUE, but not both |
| Is Not |
!$var1 |
TRUE if $var1 is not TRUE |
There are two different variations of "
and"
and "
or" operators because they operate at
different precedences.
Here we use an if and else statement(discussed in detail later) to use
the "
&&" logical operator:
<?php
// change these 2 values to see the results if numbers do not match in our expressions
$var1 = 43;
$var2 = 56;
if (($var1 == 43) && ($var2 == 56)) {
echo "Yes, the values produce the match we want.";
} else {
echo "No, the values do not match yet.";
}
?>
Yes, the values produce the match we want.
