PHP Operator (6) 'Comparison Operator' Example Explanation

Through the previous series of PHP operator learning, today we learn the sixth type of PHP operator "Comparison operator".

What are comparison operators used for?

Comparison operator. You understand it literally and it is used for comparison. It compares the results of two variables or expressions to determine whether they are true or false. If the result of the comparison is true, , returns true, otherwise, if the comparison result is false, returns false.

Let’s first take a look at the comparison operators in PHP

Comparison operators

##> is greater than $x>$yIf $x is greater than $y, return trueLess than or equal to $xIf $x is less than or equal to $y, return true. >=Greater than or equal to $x>=$yIf $x is greater than or equal to $y, then returns true. ==Equal$x==$yReturns true if $x is equal to $y. !=Not equal$x!=$yIf $x is not equal to $y, return true===Identical (congruent)$x===$yif $x Equal to $y, and they are of the same type, return true!==non-identity (not congruent)$x!= =$yReturns true if $x is not equal to $y and they are not of the same type

There are two comparison operators that need attention, namely "===" and "!==". If you use the "===" operator for comparison, they must not only be equal in value, but also have the same data type. For example, $a===$b means that $a and $b are not only completely equal in value, And the data types of $a and $b are also the same. ! == and === have opposite meanings, such as $a! ==$b means that $a and $b either have different values ​​or different data types.

Comparison operator example

This example uses comparison operators to compare the values ​​of variables. Set the variable $x=100, the data type is integer, and the variable $ y="100", the data type is string, compare $x and $y, use "==", "===", "!=", "!===" operators.

The code is as follows

<?php
$x=100;
$y="100";

var_dump($x == $y);
echo "<br>";
var_dump($x === $y);
echo "<br>";
var_dump($x != $y);
echo "<br>";
var_dump($x !== $y);
echo "<br>";

?>

Code running results:

The other ones are relatively simple, so I won’t do too many demonstrations here. , if you are interested, you can do it yourself. In the next section, we will explain to you the seventh type of PHP operator "Error Control Operator".

Recommended related articles:

1.PHP operators (1) "Arithmetic operators" examples explained

2.PHP operations Operator (2) "String Operator" Detailed Example Example

3.PHP Operator (3) "Assignment Operator" Example Example

4. PHP Operator (4) "Bit Operator" Example Example

5.PHP Operator (5) "Logical Operator" Example Example

Operator	Name	Example	Description
	Less than	$x	Returns true if $x is less than $y.

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