C语言 无法摆脱“此十进制常量仅在 ISO C90 中无符号”警告
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Can't get rid of "this decimal constant is unsigned only in ISO C90" warning
提问by rfgamaral
I'm using the FNV hash as a hashing algorithm on my Hash Table implementation but I'm getting the warning in the question title on this line:
我在我的哈希表实现中使用 FNV 哈希作为哈希算法，但我在这一行的问题标题中收到警告：
unsigned hash = 2166136261;
I don't understand why this is happening because when I do this:
我不明白为什么会这样，因为当我这样做时：
printf("%u\n", UINT_MAX);
printf("2166136261\n");
I get this:
我明白了：
4294967295
2166136261
Which seems to be under the limits of my machine...
这似乎在我机器的限制下......
Why do I get the warning and what are my options to get rid of it?
为什么我会收到警告以及我有哪些选择可以摆脱它？
回答by kennytm
unsigned hash = 2166136261u; // note the u.
You need a suffix uto signify this is an unsigned number. Without the usuffix it will be a signed number. Since
您需要一个后缀u来表示这是一个无符号数。如果没有u后缀，它将是一个有符号的数字。自从
2166136261 > 231 - 1 = INT_MAX,
this integer literal will be problematic.
这个整数文字会有问题。
