Position of object property in an equation

[dennisjn]

Many, many moons ago when I was avidly consuming books and other js resources I believe I was warned that when comparing an object property with a variable that that it was wise to put the object property on the lefthand side of the equation.
Is this still true for today and why, or was it just a furphy?
Thanks in advance.

[Thallius]

I see no real advantage in this recommendation. I do it mostly automatic because I find it easier to read but that only a personal feeling

[DaveMaxwell]

I think that was someone trying to come up with a “best practice” pattern. But it hold no value in terms of performance.

I could see it being placed on either side. It would depend on which one was the “standard”. I personally would put the expected value on the right, and the one being checked on the left.

i.e.

$x = "value";
if (object.property == $x) { 
   // do something
}

for ($y in $ylist) {
  if ($y == object.property) {
     // do something
  }
}

[m_hutley]

only time i could see it being an issue is if you goof up a close parenthesis location and accidentally try to reference a property of the result of an operation:
"This is a string and the value is"+ (x.prop + y)+", so there"

"This is a string and the value is"+ (y+x).prop+", so there"

or perhaps it’s just for readability; is x + y.value meant to be (x+y).value or (x+y.value)?
(Especially since Javascript is a multiline-acceptor, so you could also have written this as

x+y
.value;

and confused a whole lot of people.)

[Paul_Wilkins]

There was an attempt long ago to help protect people from accidentally using = for comparisons.

  if ($y = object.property) {
     // do something
  }

That would help to save the property from being accidentally assigned.

I see little to no value in that kind of behaviour, as has already been mentioned by others here.