Comparisons are used to check the relationship between variables and/or values. Comparison operators are used inside conditional statements and evaluate to either true or false. The most important comparison operators of PHP are:

$a == $b Equal TRUE if $a is equal to $b.
$a === $b Identical TRUE if $a is equal to $b, and they are of the same type.
$a != $b Not equal TRUE if $a is not equal to $b.
$a <> $b Not equal TRUE if $a is not equal to $b.
$a !== $b Not identical TRUE if $a is not equal to $b, or they are not of the same type.
$a < $b Less than TRUE if $a is strictly less than $b. $a > $b Greater than TRUE if $a is strictly greater than $b.
$a <= $b Less than or equal to TRUE if $a is less than or equal to $b. $a >= $b Greater than or equal to TRUE if $a is greater than or equal to $b.

Example1:
Code:

$a=5;
$b=6;
if($a==$b)
{
echo "Right";
}

else
{
echo "wrong";
}

Output:

wrong

Example2:
Code:

$a=5;
$b="5";
if($a===$b)
{
echo "Both  are same type";
}

else
{
echo "Both are not same type";
}

Output:

Both are not same type

Example3:
Code:

$a=5;
$b=6;
if($a!=$b)
{
echo "Right";
}

else
{
echo "wrong";
}

Output:

Right

Example4:
Code:

$a=9;
$b=6;
if($a>$b)
{
echo "Right";
}

else
{
echo "wrong";
}

Output:

Right

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