In some languages it's better to use it, eg. in Java you can go with:

   mString != null && mString.equals("test")

or

   "test".equals(mString)

They do the same, but the second one adds hidden `defensive programming` to prevent NPE in `equals`. Saves time AND code.

Intended usage of if(a=b) should be written as if((a=b)). Don't know what tool you use at work or at home, but most static code analysers will point you that. Try SonarQube at least.