[英]Conversion of char array to integer using atoi caused segmentation fault
I'm trying to convert a char array to an integer using atoi
. 我正在尝试使用atoi
将char数组转换为整数。 But the code below produces a segmentation fault. 但是下面的代码会产生分段错误。
CODE: 码:
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main(){
char a[10] = "1234567890";
int x,i;
for(i=0;i<strlen(a);i++){
x=atoi(a[i]);
printf("%d",x);
}
return 0;
}
What have I done wrong and is ther anything I can use instead of using atoi
? 我做错了什么,还有什么可以代替atoi
使用的?
char a[10] = "1234567890";
This leaves no room for the null terminator. 这为空终止符留出了空间。 And so strlen(a)
results in undefined behaviour. 因此strlen(a)
导致不确定的行为。 Declare a
like this: 声明a
这样的:
const char a[] = "1234567890";
or like this: 或像这样:
const char *a = "1234567890";
Subsequently, your call to atoi
is incorrect. 随后,您对atoi
的呼叫不正确。 You are meant to pass a pointer to a null terminated string. 您应该将指针传递给以空终止的字符串。 You pass a char
. 您传递了一个char
。 Perhaps you mean to pass a+i
: 也许您的意思是通过a+i
:
x=atoi(a+i);
Then again, it's not at all obvious why you are looping. 再说一遍,循环的原因一点也不明显。 What's wrong with: 有什么问题:
x = atoi(a);
Also, atoi
is a notoriously gnarly function to use. 同样, atoi
是个臭名昭著的功能。 It doesn't give you any meaningful way to detect errors in your input. 它没有提供任何有意义的方式来检测输入中的错误。 A better approach would be to use sscanf
. 更好的方法是使用sscanf
。
You might put this all together like so: 您可以像这样将所有内容放在一起:
#include<stdio.h>
int main(void)
{
const char *a = "1234567890";
for(size_t i = 0; a[i]; i++)
{
int x;
if (sscanf(a + i, "%d", &x) == 1)
{
printf("%d\n", x);
}
}
return 0;
}
The output of that is: 输出为:
1234567890 234567890 34567890 4567890 567890 67890 7890 890 90 0
But I doubt that's what you want. 但是我怀疑那是你想要的。 I suspect that you really want this: 我怀疑您真的想要这样:
#include<stdio.h>
int main(void)
{
int x;
if (sscanf("1234567890", "%d", &x) == 1)
{
printf("%d\n", x);
}
return 0;
}
The output is: 输出为:
1234567890
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