Is it possible to define a function with no argument by LAMBDA?

[Tie CHENG]

In Excel, we have functions with no argument such as PI(), RAND(), NOW().

However, it seems that we cannot define such a function by LAMBDA.

I tried in a cell `=LAMBDA(,4)()` (and expected 4 as return value), it raised a warning "You've entered too few arguments for this function".

Why cannot we define a function with no argument by LAMBDA?

[#2 · Accepted solution]

@Tie CHENG 

Yes, it seems to be possible.  e.g. given a named reference 'x'

=LAMBDA(x+1)()

returns x+1.

=LAMBDA(x+1)

returns a #CALC! error.

If you name the Lambda function INCx then the same results are obtained for

=INCx()

and

=INCx

respectively.  I think I have read of such functions being referred to as 'thunks' and would be used to pass a resource-intensive operation as a parameter without evaluating it before the result is needed.

The possibility of defining and testing for an optional parameter is being rolled out.

[#3]

Indeed, it is possible, thank you.

[#4]

@Tie CHENG 

With latest lambdas edition your sample could be like

=LAMBDA([x],4)()

which returns 4. You have no arguments but have optional parameter.

[#5]

Good to know... Thank you...

[#6]

@Tie CHENG You can actually do it just like you wanted, you just have to type the result directly, this means that:

=LAMBDA(4)() does return 4, and if you attach a parameter to it, it returns #VALUE