代码如下:
for ("k","p","c","o","f","g","s"){ my $name="$_.txt"; open IN ,"<",$name; while(<IN>){ ........ } }
会在while(<IN>)这一行报错：Modification of a read-only value
这是因为while循环里默认变量也是$_,循环外和循环内$_内容不一致，程序就会试图改变read-only value
一般多层循环，只让最内层用默认变量
Modification of a read-only value--perl语言改变只读变量问题
原文：https://www.cnblogs.com/xlij1205/p/10491346.html