php how to generate a string use letter and number?

Question

我想生成一个像'A00021'这样的字符串，长度为5，当数字大于10000时，那么像'B00001'这样的字符串，如何生成这样的字符串？

Answer 1

It might help you...

$str = "A10000";
if(substr($str,-5) >= '10000'){
    $newstr = strtoupper(chr(ord(substr($str,0,1)) + 1))."00001";
}else{
    $newstr = substr($str,0,1).substr("00000".(substr($str,-5)+1),-5);
}
echo $newstr;