Logical Operators in PHP

Introduction to Logical Operators in PHP

PHP operators are symbols which help in doing the logical operations with ease. The code generated with these operators helps in performing some specific actions. The logical operators include operators like addition (+), greater than (>), etc. which instruct the compiler to perform the necessary operation. It can check multiple operations and then determine which of the conditions are true. The values which are particular operators use are known as operands. The operators are not similar to functions, though there can be cases where they can be used as functions.

Logical Operators in PHP

Let us now look into Logical Operators in detail. We have six kinds of logical operators. They are as below:

PHP also has logical operators that help in combining conditional statements. To name a few of these they are AND, OR, NOT, etc.

1. AND (AND)

The AND operator returns true if both variables being compared are true.

<?php
$x = 100;
$y = 50;
if ($x == 100 and $y == 50) {
echo "AND is true";
}
?> 

Output:

As an example, we can take an analogy of taps and water. When both taps are not running water will not be flowing down the tap. This means that if both conditions are not satisfied or are False then the results will be False or 0. In a similar way if only one tap is closed and the line of water being the same it is not necessary that water will flow as the pipe is closed.

That means even if one condition is true the result will be False or 0. The last case is when both taps of water are running and the pipe being the same for both taps water will flow through the tap and thus the condition will be true.

2. OR (OR)

In a similar way, the OR operator works if either of the conditions is true.

<?php
$x = 100;
$y = 50;
if ($x == 100 or $y == 80) {
echo "XOR is TRUE";
}
?> 

Output:

The OR operation can be explained in a way where there are three sinks. Each sink having two taps. Not that the sinks are different for all the pairs the scenarios will be as described ahead. The first scenario will have none of the taps open which means there is no water running. That explains the condition of False or 0. The second case is where one of the taps are open. That means there is water flowing from one tap. This scenario helps you understand that if any of the two conditions are true then the result is true. The third scenario will be when both taps are open. The water will be flowing through both the taps. This explains the condition when both conditions are true then it will return true.

3. XOR

The XOR condition returns true when either or the variables are true, not both are true.

<?php
$x = 100;
$y = 50;
if ($x == 100 xor $y == 80) {
echo "XOR here!";
}
?

Output:

4. NOT

The NOT operator is used when it is required to check if a particular variable is not true. Which means we can use NOT when we have to check if any condition is not true.

<?php
$x = 100;
if ($x !== 90) {
echo "NOT is here";
}
?>

Output:

In this example, you can see that we are checking if the variable is not 90. The variable x is 100 and which is clearly satisfying the NOT condition. Due to this, we have the output which follows the condition specified and hence you see the output as ‘NOT is here.’

5. AND &&

This is similar to the AND that we saw previously. It will return value as true only when both conditions are true, or when both variables evaluate to be true.

<?php
$x = 100;
$y = 50;
if ($x == 100 && $y == 50) {
echo "&& is true!";
}
?> 

Output:

6. OR ||

Similar lines the OR condition is also the same as the OR mentioned above. This operator works even when one of the specified conditions is true. It has similar results just like the tap example mentioned previously. OR having three different sinks can fill the sink even when only one tap is open.

<?php
$x = 100;
$y = 50;
}
if ($x == 100 || $y == 80) {
echo "OR is true!";
}
?> 

Output:

In the above example, the variable x satisfies the condition specified for $x=100 and hence the result displays the message for when the result is true. Though here the condition for variable y is not being satisfied the output is displayed. This is because of the OR condition which works even if one condition is being satisfied.

Conclusion

PHP has many logical operators which make it easy to use. The PHP compiler helps in compiling these operators fast. The logical operators help in performing logical operations. These can be arithmetic operations, logical operations, string operations or array operations. PHP has a facility for performing all these operations. It helps in checking multiple conditions at one time. This saves time and increases the optimization of the PHP compiler. Hence it is advised to use these operators when working with PHP. Logical operators hence work in getting logical operations done easily. These conditions hence help you to get Boolean results and work upon them accordingly.

This is a guide to Logical Operators in PHP. Here we discuss the basic concept and different types of logical operators in PHP. You may also have a look at the following articles to learn more –

1. PHP Operators
2. PHP Array Search
3. PHP substr_replace()
4. PHP Encryption