用C什么是EOF的价值和'\\ 0' [英] What is value of EOF and '\0' in C

问题描述

我知道 EOF 和'\\ 0'的类型是整数，但如果这样不应该，他们有一个固定的值？

I know that EOF and '\0' are of type integers, but if so shouldn't they have a fixed value?

我都印制，并得到-1 EOF 0为'\\ 0'。但这些数值固定的吗？

I printed both and got -1 for EOF and 0 for '\0'. But are these values fixed?

我也有过这样

int a=-1;

printf("%d",a==EOF); //printed 1

是 EOF值和'\\ 0'固定的整数？

推荐答案

EOF 是扩展到使用类型整型常量前pression宏 INT 和实施相关的负值，但很常用-1。

EOF is a macro which expands to an integer constant expression with type int and an implementation dependent negative value but is very commonly -1.

'\\ 0'是字符在C值0 ++和 INT 在C值0。

'\0' is a char with value 0 in C++ and an int with the value 0 in C.

为什么的printf（％d个，一== EOF）的原因; 导致 1 是因为你没有指定值 EOF 到 A 。相反，你检查是否 A 等于 EOF 既然这是真的（ A == -1 == EOF ）它印 1 。

The reason why printf("%d",a==EOF); resulted in 1 was because you didn't assign the value EOF to a. Instead you checked if a was equal to EOF and since that was true (a == -1 == EOF) it printed 1.

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