What you are seeing is people taking specific C codying styles into other languages. This is a cargo-cult style and probably in detriment of your code base.
On the other hand, it makes perfect sense in a C code base. The purpose of this is to transform a semantic error into a syntactic error. In C, both this expressions are legal but semantics is different:
if (A == B) //Compare B to A, decide on boolean result
if (A = B) //Assign B to A, then cast B's type
//into a boolean value (non-zero true,
//zero false) and decide on that.
In theory, it should be possible to identify every instance of A=B, but then it is hard to tell if it is a typo or the actual intention of the original programmer. If you compound this with the tendency to write complicated code, you find monstrousities like this one:
if (!A & B = C == D || E == F = G)
I am sure there's a language lawyer that can tell you for sure that the above means. I, on the other hand, can only be sure that this will compile as long as B and F are L-values.
Putting constants before variables in comparisons is relevant in Javascript for the same reasons that it is in C. Perhaps even more so, since the browser compiling the code won't have -Wparentheses to lean on
What you are seeing is people taking specific C codying styles into other languages. This is a cargo-cult style and probably in detriment of your code base.
On the other hand, it makes perfect sense in a C code base. The purpose of this is to transform a semantic error into a syntactic error. In C, both this expressions are legal but semantics is different:
if (A == B) //Compare B to A, decide on boolean result
if (A = B) //Assign B to A, then cast B's type //into a boolean value (non-zero true, //zero false) and decide on that.
In theory, it should be possible to identify every instance of A=B, but then it is hard to tell if it is a typo or the actual intention of the original programmer. If you compound this with the tendency to write complicated code, you find monstrousities like this one:
if (!A & B = C == D || E == F = G)
I am sure there's a language lawyer that can tell you for sure that the above means. I, on the other hand, can only be sure that this will compile as long as B and F are L-values.