compare two string using stryncmp

[Nkhosinathie]

i'm comparing two string using the function stryncmp,but my problem is when i execute the program it doesn't give me the correct values.actually it gives me same results as the function strycmp

this is the code i did.

include<iostream>
using namespace std;
//#include<stdio.h>
#include<string.h>
int main()
{
char str1[10] = "XYZ";
char str2[10] = "XYZ";
char str3[10] ="BIRTHDAY";
 
cout<<"enter the first of two strings of your choice\n";
cin>>str1;
cout<<"enter the second string of your choice\n";
cin>>str2;
 
cout<<str1<<"\t";
cout<<"and"<<"\t";
cout<<str2<<"\t";
 
 
 
 
 
if(strncmp(str1,str2,20)==0)
 
{
cout<<"are equal\n";
}
else
{
cout<<"are Not equal\n";
}
return 0;
}

[Savage]

That's because you have set count to 20.

If one of your strings has less than count then comparison will stop on the first reached string terminator.

Lower the count to 10 and it should work

Savage

[Nkhosinathie]

That's because you have set count to 20.

If one of your strings has less than count then comparison will stop on the first reached string terminator.

Lower the count to 10 and it should work

Savage

i've changed that 20 to 10,may i ask? is the function comparing the length of the string or it is comparint whether the strings are same names?

[Savage]

i've changed that 20 to 10,may i ask? is the function comparing the length of the string or it is comparint whether the strings are same names?

It compares both.If length of two strings is not the same there is no chance that string would be same, so it returns from the function.If lengths are same,then it compares it's values.

Savage

[Nkhosinathie]

It compares both.If length of two strings is not the same there is no chance that string would be same, so it returns from the function.If lengths are same,then it compares it's values.

Savage

thank you so much for the help,it means i've finish the first of the ten programs of my assignment. thank you

[Savage]

thank you so much for the help,it means i've finish the first of the ten programs of my assignment. thank you

I'm more than happy to help you.

Savage

[Nkhosinathie]

I'm more than happy to help you.

Savage

thank you so much Savage i really appreciate your assistance while learning from you.

[Savage]

thank you so much Savage i really appreciate your assistance while learning from you.

Thank you very much,Nkhosinathie :D

Savage

[weaknessforcats]

Not true:

It compares both.If length of two strings is not the same there is no chance that string would be same, so it returns from the function.If lengths are same,then it compares it's values.

It compares corresponding characters so long as they match and one of them is not a null terminator. This is a typical implementation:

int strcmp(const char* s1, const char* s2)
{
    while(1)
    {
         if (*s1 < *s2) return -1;
         if(*s1 > *s2) return +1;
         if(*s1 == '\0') return 0;
         ++s1;
         ++s2;
    }
}
 

You do not need to know the lengths of the strings in order to compare them.

strncmp() just has a limit on the loop. If the loops runs the correct nunber of cycles, the function returns zero.