<?php
if( $var == 'ok')
{
print 'test';

}
else{
print 'refuse';
}
?>

<?php
if($var == 'ok') //if the variable named $var is equal to ok
{
print 'test'; //so we display the result 

}
else{ // else we display another message
print 'refuse';
}
?> 

<?php
$variable = 'car';

if($variable == 'car'){

print 'good! you found it';
}
elseif($variable =='bike'){
print 'you are so close!';

}
else {
print 'it\'s not the answer, try again';
} 

<?php
switch($operation)

{
case '1': // If the variable equal to 1
print ' operation number 1'; // display this phrase
break; // we close this case

case '2':// If the variable equal to 2
print 'operation number 2';
break;

default: // If the variable doesn't have any value
print 'operation by default'; // Display something by default
}
?>