Concatenating n characters from source string to destination string in C

Problem

Write a C program to concatenate n characters from source string to destination string using strncat library function

Solution

The strcat function

• This function is used for combining or concatenating two strings.

• The length of the destination string must be greater than the source string.

• The resultant concatenated string will be in the source string.

Syntax

strcat (Destination String, Source string);

Example 1

#include <string.h> main(){    char a[50] = "Hello";    char b[20] = "Good Morning";    clrscr ( );    strcat (a,b);    printf("concatenated string = %s", a);    getch ( ); }

Output

Concatenated string = Hello Good Morning

The strncat function

• This function is used for combining or concatenating n characters of one string into another.

• The length of the destination string must be greater than the source string.

• The resultant concatenated string will be in the destination string.

Syntax

strncat (Destination String, Source string,n);

Example 2

#include <string.h> main ( ){    char a [30] = "Hello";    char b [20] = "Good Morning";    clrscr ( );    strncat (a,b,4);    a [9] = ‘\0’;    printf("concatenated string = %s", a);    getch ( ); }

Output

Concatenated string = Hello Good.

Example 3

#include<stdio.h> #include<string.h> void main(){    //Declaring source and destination strings//    char source[45],destination[50];    //Reading source string and destination string from user//    printf("Enter the source string :");    gets(source);    printf("Enter the destination string before :");    gets(destination);    //Concatenate all the above results//    destination[2]='\0';    strncat(destination,source,2);    strncat(destination,&source[4],1);    //Printing destination string//    printf("The modified destination string :");    puts(destination); }

Output

Enter the source string :TutorialPoint Enter the destination string before :C Programming The modified destination string :C Tur