Is '\0' in the middle of a string can be recognized as the end of a string in C?

Question

I know in C '\0' is always at the end of a string, but is '\0' always mark the end of a string?

Just like "1230123" can be recognized as "123"?

^{One edition of the question used the notation '/0' instead of '\0'.}

String definition in [G4G](https://www.geeksforgeeks.org/strings-in-c-2/) : Strings are defined as an array of characters. The difference between a character array and a string is the string is terminated with a special character `\0`. There is an extra terminating character which is the Null character `\0` used to indicate termination of string which differs strings from normal character arrays. — EsmaeelE, Jan 24 '19 at 03:43

score 2 · Answer 1 · answered Jan 24 '19 at 02:08

2

A byte with the value 0 by definition marks the end of a string. So if you had something like this:

char s[] = { 'a', 'b', 'c', '\0', 'd', 'e', 'f', '\0' };
printf("%s\n");

It would print abc.

This is different from "1230123" where the 4th character in the string is not the value 0 but the character '0', which has an ASCII code of 48.

answered Jan 24 '19 at 02:08

dbush

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Great answer, and i suggest to add [link](https://ascii.cl/) to [ASCII](https://en.wikipedia.org/wiki/ASCII) table that illustrate `\0` as ASCII code of NULL and 48 as ASCII code of `0`. – EsmaeelE Jan 24 '19 at 03:36
@EsmaeelE But, it is unlikely that when any user runs the program, the program will have the locale for the C standard library's string functions is set to ASCII. Programs that depend on characters having specific character codes (other than 0) are, um—to put it kindly—"overly specific". – Tom Blodget Jan 24 '19 at 08:16

H.S. · Answer 2 · 2019-01-24T02:53:47.417

The null terminating character is represented as \0 and not /0 and it always mark end of string because, in C, strings are actually one-dimensional array of characters terminated by a null character \0.

This

char s[] = "1230123";

is same as this

char s[] = {'1', '2', '3', '0', '1', '2', '3', '\0'};
                            |                    |
                    This is character '0'        |
                    whose decimal value is 48    |
                                                 |
                                     This is null terminating character
                                     whose decimal value is 0

Check this example:

#include <stdio.h>

int main (void)
{
    int x,y,z;
    char s1[] = "1230123";
    char s2[] = {'1','2','3','\0','4','5','6','\0'};
    printf ("%s\n", s1);
    printf ("%s\n", s2);
    return 0;
}

Output:

1230123
123      <======= The characters after null terminating character is not printed.

chux - Reinstate Monica · Answer 3 · 2022-05-23T03:46:16.440

2

A string literal can have a '\0' in the middle.

A string only has a '\0' at the end.

'\0' is the null character and has a value of 0. '0' is the character zero.
See value of '\0' is same ... 0?

C has, as part of the language, string literals.

The two string literals below have a size of 8: the 7 you see plus the 1 not explicitly coded trailing null character '\0'.

"abc-xyz"    // size 8
"abc\0xyz"   // size 8

C, as part of the standard library, defines a string.

A string is a contiguous sequence of characters terminated by and including the first null character.

Many str...() functions only work with the data up to the first null character.

strlen("abc-xyz")  --> 7
strlen("abc\0xyz") --> 3

edited May 23 '22 at 03:46

answered Jan 24 '19 at 04:35

chux - Reinstate Monica

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I liked that you used string syntax for showing the use of '\0' in the middle of a string, rather than array of chars syntax, like the other answers. Somehow, using string syntax makes it more clear that '\0' has the same "citizen range" as any other escape sequences. – cesss Nov 03 '22 at 11:42

Is '\0' in the middle of a string can be recognized as the end of a string in C?

3 Answers3