作者sixth (12345(6))
看板Perl
标题[问题] eval for string
时间Fri Jul 19 10:12:51 2019
请问如何让范例2 像 范例1 一样，印出计算结果?
范例1:
eval '$sum = ((0x1 << 8) -1)';
print "The sum is $sum\n";
==> 会印出 255
范例2:
$str_test = "((0x1 << 8) -1)";
eval '$sum = $str_test';
print "The sum is $sum\n";
==> 会印出 (0x1 << 8) -1)
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