在c中为字符串分配内存？

Question

How do i allocate the memory for a given char array *bla in c?

blaarray = (char*)malloc(strlen(bla)*sizeof(bla));

or

blaarray = (char*)malloc(strlen(bla)*sizeof(char*));

or neither?

thanks

**note edits to reflect silly typo. I accidently pasted the options incorrectly

Answer 1

If you want blaarray to be of the same size as the string bla

blaarray = malloc((strlen(bla)+1) * sizeof(char));

Now let me explain some points.

1) To get the length of a string, use only strlen() not sizeof

2) 1 has to be added because strlen() does not include the \\0 character while returning the length

3) char* is a pointer to char , to get size of a char , one should do sizeof(char)

4) Off course you need to declare blaarray , which you can do like

char* blaarray;

5) You do not need to cast the return of malloc() , see this .

6) sizeof(char) is 1, so you can skip that.

So, all in all your code should look like.

char* blaarray;
blaarray = malloc((strlen(bla)+1));