Question

Which is better in accessing a property value?

Accessing like this

propertyobjA.objB.Prop1
propertyobjA.objB.Prop2

or assign to var

var objB = propertyobjA.objB;
then call objB.Prop1 and objB.Prop1

Which one improves performance in c#?

Answer 1

The impact to performance largely depends on the implementation of the propertyObjA.objB property getter. For instance, if it is simply implemented as:

public Foo objB { get { return this._objB; } }

Then calling that twice will have a negligible impact on performance.

If, however, that same property did something computationally expensive, then your second suggestion would perform better.

That being said, the framework guidelines state that you should not use property getters to hide potentially computationally expensive operations, instead preferring a method call instead, e.g.:

public objB ComputeB ();