PHP六种数组排序的方式

$string=array("M","B","A");
sort($string);
print_r($string);123

$string=array("M","A","C");
sort($string);
print_r($string);123

$person_age=array("john"=>"28","piter"=>"25","davies"=>"30");
asort($person_age);
print_r($person_age);123

$person_age=array("john"=>"28","piter"=>"25","davies"=>"30");
ksort($person_age);
print_r($person_age);123

$person_age=array("john"=>"28","piter"=>"25","davies"=>"30");
arsort($person_age);
print_r($person_age);123

$person_age=array("john"=>"28","piter"=>"25","davies"=>"30");
krsort($person_age);
print_r($person_age);