Scanf检测前导0 [英] Scanf detect leading 0

问题描述

我想知道如何检测输入是否有前导零。

I would like to know how to detect if input got leading zeroes or not.

scanf("%d", &d);

这只会改变07到7等。

This will just change 07 to 7 etc..

最后我想返回（1）如果输入有前导零并且如果输入正常则返回（0）。

In the end i would like to return(1) if input got leading zeroes and return(0) if the input is ok.

谢谢。

推荐答案

如果您想知道数字是否有前导零，您必须将其作为字符串读取，并自行进行验证。字符串 07 只是表示性的，当存储为整数时，它只存储为 7 。

If you want to know if a number have leading zeros you have to read it as a string, and make the verification yourself. The string 07 is just presentational, when stored as an integer it's stored as just 7.

要验证您读取的字符串是带有前导零的整数，您可以先使用 strtol 检查它确实是一个有效的整数。然后检查字符串中的第一个字符是否为'0'。

To verify that the string you've read is an integer with leading zeros, you can first use strtol to check that it is indeed a valid integer. Then just check if the first character in the string is a '0'.

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