Segmentation Fault, Array Printing C

Question

I am trying to write a program that takes user-input strings and prints them out as a 7 by 5 asterisk grid. I am currently trying to figure out how to print put the letters as I need to print them line by line in order for the different letters to be printed side by side.

Anyway, my attempt so far is this:

#include <stdio.h>
#include <string.h>


char capitalA[7][5] = { 
"  *  ",
" * * ",
"*   *",
"*****",
"*   *",
"*   *",
"*   *"
};
int i;
int j;

int main() 
{//main

    for (i = 0; i < 5 ; i++) 
    {
        for (j = 0; j < 7 ; j++) 
        {
            printf("%s\n", capitalA[j][i]);
        }
    }
    return (0);
}//*main

My desired output is the asterisk A, but I get a Segmentation fault.

%s --> %c (voting to close as a typo).

Sergey Kalinichenko
– Sergey Kalinichenko

2015-10-24 11:42:28 +00:00
Commented Oct 24, 2015 at 11:42 — Sergey Kalinichenko
– Sergey Kalinichenko, Commented Oct 24, 2015 at 11:42

vsoftco · Accepted Answer · 2015-10-24 12:42:42Z

4

char capitalA[7][5]

is not large enough. The strings literals you use in the initialization automatically include the \0 character, so you need to use

char capitalA[7][6]

instead. And change your loops to a single one

for (j = 0; j < 7 ; j++)
    printf("%s\n", capitalA[j]);

since right now you are displaying chars using %s specifier.

If you're not happy with the '\0' being added automatically and need to save space, you can use the code you currently have or you need to initialize the array using brace initialization like

char capitalA[7][5] = {{' ', ' ', '*', ' ', ' '}, ...};

and stick to displaying the characters char by char (making sure that you use the '%c' specifier instead of the '%s').

edited Oct 24, 2015 at 12:42

answered Oct 24, 2015 at 11:41

vsoftco

56.9k12 gold badges150 silver badges269 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

vsoftco Over a year ago

@MiguelRestrepo It should work fine, see the live example here.

Michael Atkinson Over a year ago

Well then I don't know what is wrong with my compiler, but thank you anyway.

Spikatrix Over a year ago

@MiguelRestrepo Did you do exactly what vsoftco told to? Could you share your new code which segfaults?

vsoftco Over a year ago

@MiguelRestrepo Can you copy paste the code in the live example I just linked and try it? There is no reason to get a segfault.

Michael Atkinson Over a year ago

Wow, that was stupid. I'm sorry, I forgot to remove the [i] from the printf statement after deleting the i for loop.

|

Spikatrix · Accepted Answer · 2015-10-24 11:52:50Z

2

This:

for (i = 0; i < 5 ; i++) {
    for (j = 0; j < 7 ; j++) {
        printf("%s\n", capitalA[j][i]);
}
}

should be

for (i = 0; i < 7; i++) {
    for (j = 0; j < 5; j++) {
        printf("%c", capitalA[i][j]);
    }
    printf("\n");
}

because

The correct format specifier for a char is %c, not %s.
You mixed up the loops. The outer one should loop 7 times while the inner one should loop 5 times.
You should print a \n after the inner loop has finished executing and not in each iteration of the inner loop.

answered Oct 24, 2015 at 11:52

Spikatrix

20.3k7 gold badges44 silver badges85 bronze badges

Comments

Gopi · Accepted Answer · 2015-10-24 11:41:25Z

1

printf("%s\n", capitalA[j][i]);

should be

printf("%c", capitalA[j][i]);

What you need is to print character by character but you are trying to print a string using %s which tries to print a string until \0 is encountered.

Since %s is trying to access array out of bound you see a segmenation fault.

If you want to go with printing char by char then make sure you insert \n after each row

answered Oct 24, 2015 at 11:41

Gopi

19.9k4 gold badges28 silver badges37 bronze badges

Comments

Mukit09 · Accepted Answer · 2015-10-24 12:03:42Z

0

 for (i = 0; i < 5 ; i++) 
 {
    for (j = 0; j < 7 ; j++) 
    {
        printf("%s\n", capitalA[j][i]);
    }
 }

You are printing char type array. Not a single character. Change it to

for (i = 0; i < 5 ; i++) 
{
    for (j = 0; j < 7 ; j++) 
    {
        printf("%c", capitalA[j][i]);
    }
    printf("\n");
}

edited Oct 24, 2015 at 12:03

answered Oct 24, 2015 at 11:41

Mukit09

3,4495 gold badges30 silver badges46 bronze badges

1 Comment

Michael Atkinson Over a year ago

This prints each character and then start a newline. Which means I get blank lines and lines with single asterisks.

Hamza Jabbour · Accepted Answer · 2015-10-24 12:54:49Z

0

just use one for loop, and change 5 to 6 in the array declaration like this :

char capitalA[7][6]
//  and
for(j=0 ; j<7 ; j++)
    printf("%s\n",capitalA[j]);

your program will be like this after modification, try it ^^:

#include <stdio.h>
#include <string.h>

//edit the column nomber to support the '\0' it will be 6 not 5.
char capitalA[7][6] = { 
"  *  ",
" * * ",
"*   *",
"*****",
"*   *",
"*   *",
"*   *"
};
int i;
int j;

int main() 
{//main


        for (j = 0; j < 7 ; j++) 
        {
            printf("%s\n", capitalA[j]);
        }

    return (0);
}//*main

edited Oct 24, 2015 at 12:54

answered Oct 24, 2015 at 12:49

Hamza Jabbour

5144 silver badges7 bronze badges

Collectives™ on Stack Overflow

Segmentation Fault, Array Printing C

5 Answers 5

8 Comments

Comments

Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

8 Comments

Comments

Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related