Arcade Expression Bool Error

[PMaddocks]

Hey everyone,

I am new to using Arcade. I'm getting a Bool error, not sure why. Any help or suggestions appreciated. Thank you

var a = $feature.WSE2yrEx;
var b = $feature.WSE2yrAlt;
var x = When(a = b, 'grey', a = null, 'green', b = null, 'green', a - b > 0.5, 'orange', 'red');
return x;

[jcarlson · Accepted solution]

In your "When" function, the conditions need to use "==" to compare values. A single "=" is for assigning values to variables.

[jcarlson]

Oh and a won't be equal to null. You'll have to use IsEmpty(a) instead a = null, etc.