What is the meaning of a "*" before a string in C?

Question

I am trying to understand this algorithm, which reverses a C-style character in-place. I don't understand what the * indicates in the context of being before a string and in the context of "char * end." Thanks for your help!

void reverse(char *str) {
    char * end = str;
    char tmp;
    if (str) {
        while (*end) {
        ++end;
        }
        --end;
        while (str < end) {
            tmp = *str;
            *str++ = *end;
            *end-- = tmp;
        }
    }
}

It's a pointer to a type of `char`...been a while, but it would appear to be doing some pointer arithmetic, walking between sequential memory locations — MadProgrammer, Nov 07 '14 at 07:09
Thanks---I'm brushing up on my Java, and I just could not remember ever seeing these asterisks. Well, there's that question answered. — Chloe, Nov 07 '14 at 07:14
Possible duplicate of [What is the difference between char s\[\] and char \*s in C?](http://stackoverflow.com/questions/1704407/what-is-the-difference-between-char-s-and-char-s-in-c) — Teepeemm, Nov 05 '15 at 17:14

Chris Maes · Answer 1 · 2014-11-07T08:36:30.483

0

the asterisk refers to a pointer

char tmp

this is a character

char * str

this is a pointer to a char (or char array in this case).

tmp = *str;

means that the character tmp is filled with the first character from the string array pointed to by the pointer str.

edited Nov 07 '14 at 08:36

answered Nov 07 '14 at 07:18

Chris Maes

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2

`this is a pointer to a char array.` No, it's a pointer to a character. That character may or may not be the first character in a character array. – Iskar Jarak Nov 07 '14 at 07:44

score 0 · Answer 2 · answered Nov 07 '14 at 07:24

You are really interested in learning then you need to learn basic of c first then pointer:

This one is a very quick tutorial of pointers : http://www.programiz.com/c-programming/c-pointers then go through this and see string as pointer : https://www.cs.bu.edu/teaching/c/string/intro/

I will suggest to go through them once help you in understanding many things in other languages also. :)

score 0 · Answer 3 · answered Jul 22 '15 at 15:43

0

It's a character pointer when you use a "" before a string.. This is also treated as character array where the string entered after"" will be the name of that array.

answered Jul 22 '15 at 15:43

Koushik MUSUNURI

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What is the meaning of a "*" before a string in C?

3 Answers3