php! 연산자
$a == $b Equal TRUE if $a is equal to $b after type juggling.
$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 after type juggling.
$a <> $b Not equal TRUE if $a is not equal to $b after type juggling.
$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.
$a <=> $b Spaceship An integer less than, equal to, or greater than zero when $a is less than, equal to, or greater than $b, respectively. Available as of PHP 7.
숫자보다 작은 경우 php
<?php
if ($a > $b)
echo "a is bigger than b";
?>
php 삼항
#Ternary & Shorthand Syntax
<?php
$loggedIn = false;
$array =[1,2,3,4,5,6];
if($loggedIn){
echo 'You are logged in';
echo '<br>';
}else {
echo 'You are NOT logged in';
echo '<br>';
}
//the below is the same thing as above
echo ($loggedIn) ? 'You are logged in' : 'You are NOT logged in';
$isRegistered = ($loggedIn == true) ? true : false;
echo '<br>';
echo $isRegistered;
//these can be nested too
$age = 9;
$score = 15;
echo'<br>';
echo 'Your score is: '.($score > 10 ? ($age >10 ? 'Average': '
Exceptional'): ($age > 10 ? 'Horrible':'Average'));
echo'<br>';
?>
//alternative syntax for conditionals and loops
<!-- alternative syntax for conditionals and loops -->
<div>
<?php if($loggedIn) { ?>
<h1>Welcome User</h1>
<?php }else{ ?>
<h1>Welcome Guest</h1>
<?php } ?>
</div>
//<!-- a better way that looks better -->
<div>
<?php if($loggedIn): ?>
<h1>Welcome User</h1>
<?php else: ?>
<h1>Welcome Guest</h1>
<?php endif; ?>
</div>
//<!-- An Array can be used too -->
<div>
<?php foreach($array as $val): ?>
<?php echo $val; ?>
<?php endforeach; ?>
</div>
//<!-- Can also use loops this way -->
<div>
<?php for($i = 0; $i < 10; $i++): ?>
<li> <?php echo $i; ?></li>
<?php endfor; ?>
</div>
php 의 연산자
if (condition)
code to be executed if condition is true;
else
code to be executed if condition is false;
php?:
// Example usage for: Ternary Operator
$action = $_POST['action'] ?: 'default';
// The above is identical to this if/else statement
if (empty($_POST['action'])) {
$action = 'default';
} else {
$action = $_POST['action'];
}