Check if input is float else stop

Question

scanf(\"%f\", &num);

I have to check if thats a valid float variable and stop executing if it has symbols like @ or !

Answer 1

You can check the return value from scanf(). If you look at this page :

Return value

On success, the function returns the number of items of the argument list successfully filled. This count can match the expected number of items or be less (even zero) due to a matching failure, a reading error, or the reach of the end-of-file.

So something like :

if ( scanf( "%f", &num ) <= 0 )
{
    // Stop the execution
}
// Continue

will do what you want.