Why if statement is executing in this code?

Question

https://code.sololearn.com/cCY2qy1CbxTS/?ref=app

Answer 1

When a string literal (even an empty one) is used in an evaluation e.g. an `if` conditional; the memory address of the literal is used instead.

Try to print the address and you'll see it's non zero even though it's an empty string literal.

printf( "%p\n", "" );

And as you probably know already, a non zero value is considered truthy, and thus the `if` block is chosen.

On the contrary, if you try to get the first char off the empty string literal; you'll get a zero ('\0' when being represented as a char) because the literal was empty. And therefore you'll end up entering the `else` block because a zero is considered falsy.

if( *"" ) // evaluates to false

Hope I get it right ...

Answer 2

Ipang you mean if we use * then it will use value inside double quotation and writing without * will use address of given string ...* will point out value of empty string am I right ?

Answer 3

- A snippet showing example of evaluation involving `cout` is still closely related to your recent question

https://www.sololearn.com/Discuss/3026360/?ref=app.

If you read the link in Jayakrishna's answer in that post you'll understand why it is so

if( !cout << true ) // recommend to use parentheses if( !( cout << true ) )

- As for the evaluation of '¥0'
It's not a valid char literal because it contains more than one character. You should be getting a warning about this I suppose.

- About the use of * (indirection or dereference), I suppose a web search on pointer and pointer arithmetic might provide you a better explanation than any I could ever do : )

Answer 4

// Online C++ compiler to run C++ program online
#include <iostream>
using namespace std ;
int main() {
if(!cout<<true){
cout <<"True ";
}
else {cout <<"False";}

return 0;
}

In this code, condition in if statement is not executing why?

Answer 5

#include <iostream>
using namespace std ;
int main() {
if('¥0'){
cout <<"True ";
}
else {cout <<"False";}

return 0;
}

This code is also executing True condition ..