PHP Operators Interview Questions & Answers

How will you concatenate two strings in PHP?

To concatenate two string variables together, use the dot (.) operator.

What is the difference between == and === Operators in PHP?

PHP equal operator (==) and idential operator (===) are Relational or Comparison Operators in PHP langauge.

The only difference is that === operator matches the values along with Data types. While == operator only match values but not Data types.

Example to see difference between both operators

<?php
 
$num_1 = 12;
$num_2 = 12.00;
 
if ($num_1 == $num_2) {
    echo "Value matched using ==";
} else {
    echo "Value is not matched using ==";
}
 
echo "<br> Now we will check using === operator <br>";
 
if ($num_1 === $num_2) {
    echo "Value is matched using ===";
} else {
    echo "Value is not matched using ===";
}
 
?>

We have compared the two variable one by one by using == and === Operator, we get the following result.

You will see that value is matched if used the equal operator '==‘ and not matched if used identical operator '===' because data type is not same for both numbers.

Therefore, if we need to match both values strictly with datatypes, '===' operator will be used else '==' will be used in PHP.