String-Operations-using-User-Defined-Functions

A C program to implement following operations on string using user-defined functions: Comparison of Two Strings, Copying One String into Another, Finding the String Length, Concatenating Two Strings into One.

#include<stdio.h>
int StringCopy(char* a,char* b);
int StringLength(char* a);
int StringCompare(char* a, char* b);
int concatenate(char* str1, char* str2);
int main()
{
char string[20];
printf("Enter the string:\n");
scanf("%s",&string);
int len=StringLength(string);
printf("The length of the string is: %d\n",len);

char string1[20];
printf("\nEnter the string to be copied:\n");
scanf("%s",&string1);
char string2[20];
StringCopy(string1,string2);
printf("The copied string is: %s\n",string2);

char strA[20], strB[20];
printf("\nEnter first string to compare:\n");
scanf("%s", strA);
printf("Enter second string to compare:\n");
scanf("%s", strB);
int compare = StringCompare(strA, strB);
if (compare == 1)
    printf("Strings are equal.\n");
else
   {
      printf("Strings are not equal.\n");
   }
   
 char str1[100],str2[100];  

printf("\nConcatenated String: %s", str1);
printf("\nEnter first string:\n");
scanf("%s",&str1);
printf("\nEnter second string:\n");   
scanf("%s",&str2); 
concatenate(str1,str2);
printf("The concatenated string is: %s",str1);
   
return 0;
}
int StringLength(char* a)
{
int i=0;
while(a[i]!='\0')
{
    i++;
}
return i;
}
int StringCopy(char* a,char* b)
{
int i=0,j=0;
while(a[i]!='\0')
{
b[j]=a[i];
i++;
j++;
}

}
int StringCompare(char* a, char* b)
{
int i = 0;
while (a[i] != '\0' && b[i] != '\0') {
     if ((int)a[i] != (int)b[i]) {
        return 0; 
    }
    i++;
}
if (a[i] == '\0' && b[i] == '\0') {
    return 1; 
} else {
    return 0; 
}
}
int concatenate(char* str1, char* str2) {
int i = 0, j = 0;
while (str1[i] != '\0') i++;
while (str2[j] != '\0') {
    str1[i] = str2[j];
    i++; j++;
}
str1[i] = '\0';
}