<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<?php
$z=adbqhwbqjuyguqwgyquiwguyquwehqwuiepoqiuwepoqiuwpoiqwepiqwruweroiuyiqazxswedcvfrtgbnhyujmkilopplmkoijnbhuygvcftrdxzsewqa;
$a="abcdefghijklmnopqrstuvwsyz";
for($i=0;$i<strlen($a);$i++){$s=$a[$i];
$b=0;
for ($j=0;$j<strlen($z);$j++){ if ($a[$i]==$z[$j]){$b+=1;
}
}
echo $a{$i}."出现的次数:".$b."<br>";}
?>
1
</body>
</html>
# PHP
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
Random uppercase letters chr(rand(65,90)); Random lowercase letters chr(rand(97,122)); can simplify entering so many characters