How do I check if an instance has a certain property?

Title says it all

To explain:

local property = "Name"; -- Name is a property every instance has.

for i,v in next, workspace:GetChildren() do
	if (v[property]) then
		print("found: "..tostring(v)..";\n    property: "..tostring(property));
	end
end

The above doesn't error because every instance in workspace has a property "Name"...

However:

Instance.new("StringValue", workspace);

local property = "Value"; -- Not every instance has this property 

for i,v in next, workspace:GetChildren() do
	if (v[property]) then
		print("found: "..tostring(v)..";\n    property: "..tostring(property));
	end
end

The above errors saying that "Value" is not a valid property of camera? Why does it error? I clearly state that IF the instance has a property of "Value", then to print. It completely ignores it.