เขียนโปรแกรม

$score=65; if($score < 50){echo 'grade 0';}

else if($score <55){echo 'grade 1';} 

else if($score <60){echo 'grade 1.5';}

else if($score <65){echo 'grade 2';} 

else if($score <70){echo 'grade 2.5';}

else if($score <75){echo 'grade 3';} 

else if($score <80){echo 'grade 3.5';}

else{echo 'grade 4';}