9
First type of statement came from C/C++, where was possible to pass not boolean values to condition verification. E.g. anything not 0 was true, and zero was false:
if (5) { } // true
if (0) { } // false
Sometimes it created problems if you forgot to type one '=' char:
if (x = 5) { } // this was true always and changed x value
if (x == 5) { } // this was true, if x was equal to 5
So, Yoda syntax was used, to receive compiler error in case one '=' was missed:
if (5 = x) { } // this was generating compiler error for absent-minded programmers
if (5 == x) { } // this was true, if x was equal to 5
C# allow only boolean value in conditions, So
if (x = 5) { } // this won't compile
if (x == 5) { } // this is true, if x was equal to 5
What about boolean types?
if (y = true) { }
if (y == true) { }
Well, this is useless code, because you can just write if (y). Conclusion: Yoda syntax is gone with C/C++ and you do not need to use it anymore.