外部const char* const指针或外部const char数组[]导致链接错误
extern const char* const pointer or extern const char array[] cause link error
代码:
file1.cc
#include <stdio.h>
const char *pointerString = "pointerString";
const char arrayString[] = "arrayString";
const char* const constpointerString = "constpointerString";
extern void printString();
int main(void)
{
printString();
return 0;
}
file2.cc
#include <stdio.h>
extern const char *pointerString;
extern const char arrayString[];
extern const char* const constpointerString;
void printString()
{
printf("pointerString: %sn", pointerString);
printf("arrayString: %sn", arrayString);
printf("constpointerString: %sn", constpointerString);
}
完成命令:g++ file1。cc file2。Cc -o out错误链接:
/tmp/cczatCe9.o: In function `printString()':
file2.cc:(.text+0x1f): undefined reference to `arrayString'
file2.cc:(.text+0x30): undefined reference to `constpointerString'
collect2: ld returned 1 exit status
g++版本:4.6.3(Unbuntu/Linaro 4.6.3-1ubuntu5)
谁能帮忙??
将外部声明放在头文件中,并将其包含在两个源文件。在file1.cc
中,arrayString
和constpointerString
具有内键(因为这是const
对象的默认值),所以不能从其他翻译单位看。
extern char const arrayString[] = "arrayString";
extern char const* const constpointerString = "constpointerString";
但一般来说,最好使用标题