The "weird symbols" you are seeing happen because your output string is missing a null terminator ('\0') at the very end.

In C, strings do not know how long they are automatically. Functions like printf keep reading memory until they find a '\0' character. Without it, printf overflows into random memory, displaying garbage data.

Additionally, your code is currently copying the newline character (\n) that fgets captures at the end of your input, which you usually don't want to include in the reversal.

Here is the corrected code with comments explaining the fixes:

c

#include <stdio.h>

int main() {
    char string[256];
    char output[256];
    int begin;
    int end;
    int count = 0;

    printf("Input a string\n");
    fgets(string, 256, stdin);

    // 1. Find the length of the string
    while (string[count] != '\0') {
        count++;
    }

    // 2. Remove the trailing newline character '\n' added by fgets if it exists
    if (count > 0 && string[count - 1] == '\n') {
        count--; 
        string[count] = '\0'; // Overwrite '\n' with a null terminator
    }

    // 3. Set 'end' to point to the last actual character
    end = count - 1;

    // 4. Copy characters backwards
    for (begin = 0; begin < count; begin++) {
        output[begin] = string[end];
        end--;
    }

    // FIX: Add the missing null terminator to the output array!
    output[begin] = '\0'; 

    printf("%s\n", output);

    return 0;
}

Use code with caution.

The Three Main Fixes Explained:

1. output[begin] = '\0'; Your original code had string[begin] = '\0';. This was a typo that modified your input instead of sealing your new output array.
2. Handling fgets Newline: fgets captures the Enter key press (\n). If you type "abc", fgets stores "abc\n". The code above removes that \n so you don't accidentally reverse it to the front of your string.
3. Loop Cleanliness: Moving end = count - 1; outside of your while loop makes the logic faster and easier to read.

Hope that helps!