for example, the definition or constraint that a postal code must be a valid number may be missing or not enforced consistently.
例如,可能缺少邮政编码必须为有效数字的定义或约束,或者执行不一致。
for example, a postal code in the united states is a five-digit number, optionally followed by a dash and a four-digit number. listing 1 shows the regular expression that describes that format
例如,在美国邮政编码是一个五位数,后面还可能跟有一个破折号加一个四位数。
a postal code makes it easier for the post office to deliver letters.
邮政编码使得邮局送信更为容易。