我给你举个例子。假设有一个代码:
$a = "A9"; print ++$a, "\n";
$a = "bz"; print ++$a, "\n";
$a = "Zz"; print ++$a, "\n";
$a = "z9"; print ++$a, "\n";
$a = "9z"; print ++$a, "\n";
为什么输出会是这样的:
B0
ca
AAa
aa0
10
不是这样的:
B0
ca
Aa
a0
0a
我给你举个例子。假设有一个代码:
$a = "A9"; print ++$a, "\n";
$a = "bz"; print ++$a, "\n";
$a = "Zz"; print ++$a, "\n";
$a = "z9"; print ++$a, "\n";
$a = "9z"; print ++$a, "\n";
为什么输出会是这样的:
B0
ca
AAa
aa0
10
不是这样的:
B0
ca
Aa
a0
0a
如果变量仅在字符串上下文中使用,具有值,并且不是空字符串,并且匹配模式:
/^[a-zA-Z] [0-9] $/
然后自动增量将在其范围内执行,并添加一个字符(带换行):