如何在C中声明多行字符串

Question

#include <stdio.h>
#include <string.h>

int main() 
{
    char string[] = "firstline of string\n"
              +" second line of string\n"
              +" third line of string\n"
              +"  fourth line of string\n"

int k = strlen(string);
return 0;
}

如何在C中多行声明字符串？

此代码给我错误