c programming

Question

#include<stdio.h>
int main()
{
    
    if(*"abc" ==*"abcdef")
    printf("strings are equal");
    else
    printf("not equal");
    return;
}

Can someone please explain this program as output is strings are equal?

Comments

what is the meaning of  *"abc" ?

---

I dont know , better you should run on compiler as it is giving strings are equal as an output.

---

#include<stdio.h>
#include<conio.h>

main()

{
    
    if("a")
    
    printf("strings are equal");
    
    else
    
    printf("not equal");
    
    getch();
    
    return 1 ;
}

 

This is also printing the same "strings are equal"

---

because ascii value of a is not zero hence it will represent the true condition

Answer 1

"abc" is a array of characters  hence *"abc " represents the value at starting address of the array which is same for both *"abc" and *"abcdef" .

 

Just print both *"abc" and *"abcdef " in c it will print the ascii value  of a  or a .

Comments

how do u know starting address will be equal?

both are different string, right?

---

Not the starting address ,  value at the staring address is compared.

---

@vashisht,Brother I've a slight doubt in mind regarding your explanation. Like you've said that the value at starting address is compared. So undoubtedly is equal,however, one thing to note is that abc terminates with a NULL value and in the second string "def" is present. So after c the comparison stops?

---

let A="abc"
     B="abcdef"

both are character arrays now A will give the starting address of string "abc" and B will give the starting address of "abcdef".
Now *A will give the value at the  starting address of array A
*B will give the the value at the starting address of array B

Answer 2

Both are pointers to Strings pointing to the same first element i.e. "a" , It will print 97 , the ASCII value to "a" for both and comparison will result in TRUE . If we change the first element both the values will not match and output will be "not equal".

#include<stdio.h>
#include<conio.h>

main()

{
  
    printf("Value of %d \n ", *"a"); // Will print 97
    printf("Value of %d \n", *"abcd"); // Will print 97
  
    if(*"a"==*"abcd")   // TRUE
      
    printf("strings are equal");
    
    else
    
    printf("not equal");
    
    getch();
    
    return 1 ;
}
 

O/P : 

Value of 97
 Value of 97
strings are equal

Answer 3

"abc" is a string. *"abc" means pointer to starting adress of "abc", as * is dereferencing *"abc" is 'a'. 

in the same way *"abcdef" is 'a'. so it compares ascii values of both which give condition TRUE . 

Answer 4

"abc" IS A STRING CONSTANT which returns starting address of the string to a pointer(character pointer)

"abcdef" IS ALSO A STRING CONSTANT which returns starting address of the string to a pointer(character pointer)

Note that every string constant starting address is diffrent with any other string constant

if("abc"=="abcdef") ====> Starting addresses of both string constants are compared and the result is if(0)

but here *("abc") is compared with *("abcdef") therefore character of the addresses will compare it implies that if(1)