试图将字符串复制到 C 中的 const char * 数组中

Question

I am trying to convert a string in C (using the string.h library) into a const char array.

int len = sizeof(the_string);
const char *char_array = malloc(len);
strcpy(char_array, the_string);

I have pored through the string.h method file and googled it but things keep coming up in C++. Any advice would be greatly appreciated, thank you!!!

Answer 1

This declaration of a pointer

const char *char_array;

means that you may not change the memory pointed to by the pointer using the pointer.

You could make the pointer itself a constant object like

char * const char_array = malloc( some_size );

In this case you may not reassign the pointer itself but you may change the memory pointed to by the pointer.

Take into account that the expression sizeof(the_string) does not make a great sense if you are going to know the length of a string stored in a character array because in general a character array can be much larger than the stored string in it. Instead you should write

size_t len = strlen( the_string );

Using the expression sizeof(the_string) makes a sense in declarations such this

char the_string[] = "Hello";

that is when the size of a character array is determined by the size of a string literal used as an initializer.