Compare if two strings are equal in the C language.

In C language, you can utilize the strcmp function to compare if two strings are equal.

The prototype of the strcmp function is:

int strcmp(const char *str1, const char *str2);

The parameters str1 and str2 are the two strings to be compared.

If two strings are equal, the strcmp function will return 0; if str1 is less than str2, it will return a negative value; if str1 is greater than str2, it will return a positive value.

Here is an example code demonstrating how to compare if two strings are equal:

#include <stdio.h>
#include <string.h>

int main() {
   char str1[] = "Hello";
   char str2[] = "Hello";
   char str3[] = "World";
   
   if (strcmp(str1, str2) == 0) {
      printf("str1和str2相等\n");
   } else {
      printf("str1和str2不相等\n");
   }
   
   if (strcmp(str1, str3) == 0) {
      printf("str1和str3相等\n");
   } else {
      printf("str1和str3不相等\n");
   }
   
   return 0;
}

Result of execution:

str1和str2相等
str1和str3不相等