Write a program to compare two strings without using string function
#include<stdio.h>
int main() {
char str1[30], str2[30];
int i;
printf("\nEnter two strings :\n");
gets(str1);
gets(str2);
i = 0;
while (str1[i] == str2[i] && str1[i] != '\0')
i++;
if (str1[i] > str2[i])
printf("str1 > str2 alphabetically");
else if (str1[i] < str2[i])
printf("str1 < str2 alphabetically");
else
printf("str1 = str2 alphabetically");
return (0);
}
Output
Enter two strings :
nawaraj
shah
str1 < str2 alphabetically
Hey can you please explain the logic behind this while condition
str1[i] == str2[i] && str1[i] != ‘\0’
First of all, it counts from first to last.
For example, if we have two string, lets say str1 = “aserg” and str2 = “asbh”. Here, counting starts from 0 so initially ASCII values of str1[0] and str2[0] being compared means comparing ‘a’ with ‘a’, also str1[0] does not contain ‘\0’. ‘\0’ is used to indicate string end. The while condition is true, so it goes one more loop till srt1[2] and str2[2], where str1[2] = ‘e’ and str2[2] = ‘e’.
Condition fail, loop stop, and ‘i’ have value ‘2’.