CODEWITHSUNDEEP
c++string
Ghost
Ghost

Reputation: 1835

Does a pointer to a char overwrite memory when used to point to a string?

char str[]="Hello";

this allocates 6 bytes for the string , but if i write

char *str = "Hello";

will this overwrite data because it was just meant to store 1 char? So what i'm asking is that when i declare a string, but not initialize it (char str[12]; ) , do 12 bytes get reserved here or when i initialize it? And if they do get initialized here, so that means that in:

char *str;

only 1 byte gets reserved, but when i make it point to a string, doesn't that overwrite data beyond it's bounds?

Upvotes: 1

Views: 408

Answers (2)

K-ballo
K-ballo

Reputation: 81409

char str[]="Hello";

You got that right, its an array of 6 chars

char *str = "Hello";

That's a pointer to a string literal. Somewhere there is an array of 6 chars and your variable str is just pointing to it.

char *str;

This does not reserve anything, its a pointer pointing to an indeterminated place. When you make it point to a string, then it points to an array of chars that lives somewhere else, there is no copy involved.

Upvotes: 0

Ben Voigt
Ben Voigt

Reputation: 283921

char *str;

does not reserve any data for content. It is a pointer, sized to hold a memory address.

char *str = "Hello";

6 bytes for { 'H', 'e', 'l', 'l', 'o', 0 } already has been stored somewhere by the compiler. Now you are making a variable holding its address (pointing to it). The string content is not copied.

Upvotes: 2

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