60.C Program to Concatenate Two Strings

C Program to Concatenate Two Strings

To understand this example, you should have the knowledge of following C programming topics:

• C Programming Arrays
• C Programming Strings
• C Programming for Loop

You can concatenate two strings easily using standard library function strcat() but, this program concatenates two strings manually without using strcat() function.

Example: Concatenate Two Strings Without Using strcat()

#include <stdio.h>
int main()
{
    char s1[100], s2[100], i, j;

    printf("Enter first string: ");
    scanf("%s", s1);

    printf("Enter second string: ");
    scanf("%s", s2);

    // calculate the length of string s1
    // and store it in i
    for(i = 0; s1[i] != '\0'; ++i);

    for(j = 0; s2[j] != '\0'; ++j, ++i)
    {
        s1[i] = s2[j];
    }

    s1[i] = '\0';
    printf("After concatenation: %s", s1);

    return 0;
}

Output

Enter first string: lol
Enter second string: :)
After concatenation: lol:)

Check out these related examples:

• C Program to Find the Length of a String
• C Program to Copy String Without Using strcpy()
• C Program to Remove all Characters in a String Except Alphabet