C Program to Copy One String into Other Without Using Library Function.

Program : C Program to Copy One String into Other Without Using Library Function.

#include<stdio.h>

int main() {
   char s1[100], s2[100];
   int i;

   printf("\nEnter the string :");
   gets(s1);

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

   s2[i] = '\0';
   printf("\nCopied String is %s ", s2);

   return (0);
}

#include<stdio.h>

int main() {

char s1[100], s2[100];

int i;

printf("\nEnter the string :");

gets(s1);

i = 0;

while (s1[i] != '\0') {

s2[i] = s1[i];

i++;

}

s2[i] = '\0';

printf("\nCopied String is %s ", s2);

return (0);

}

Output :

Enter the string : c4learn.com
Copied String is c4learn.com

1 2	Enter the string : c4learn.com Copied String is c4learn.com

Explanation :

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

i = 0;

while (s1[i] != '\0') {

s2[i] = s1[i];

i++;

}

Scan Entered String From Left to Right , Character by Character.
In Each Iteration Copy One Character To New String Variable.
As soon as Source or Original String Ends , Process of Coping Character Stops but we still haven’t Copied NULL Character into new String so , Append Null Character to New String.

s2[i] = '\0';

1	s2[i] = '\0';

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C Program to Copy One String into Other Without Using Library Function.