Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

The Power BI DataViz World Championships are on! With four chances to enter, you could win a spot in the LIVE Grand Finale in Las Vegas. Show off your skills.

Reply
mpi_gov_vn
Frequent Visitor

What does the symbol () , =>, _ mean in M expression?

Hi guys,

 

I was reading an article on how to use List.Generate function. It mentions the symbols like "()", "=>" and "_" that I do not understand the meaning. Here's an example:

 

 

List.Generate(() => 10, each _ > 0, each _ - 1)

 

 

Could you help me explain this? Or better, is there a documentation to this? Thank you.

 

Reference: https://docs.microsoft.com/en-us/powerquery-m/list-generate

1 ACCEPTED SOLUTION
AlB
Community Champion
Community Champion

Hi @mpi_gov_vn 

You use ( )=> to declare (the start of) a function without input arguments in M. 

Check this out: https://docs.microsoft.com/en-us/powerquery-m/m-spec-functions

 

As for _  ,each is equivalent to

(_)=>

i.e. declaring (the start of) a function where _ is the input argument to the function

Read this excellent article to know more about each and _

https://www.excelguru.ca/blog/2018/01/09/each-keyword-power-query/

Please mark the question solved when done and consider giving a thumbs up if posts are helpful.

Contact me privately for support with any larger-scale BI needs, tutoring, etc.

Cheers 

 

SU18_powerbi_badge

 

View solution in original post

2 REPLIES 2
AlB
Community Champion
Community Champion

Hi @mpi_gov_vn 

You use ( )=> to declare (the start of) a function without input arguments in M. 

Check this out: https://docs.microsoft.com/en-us/powerquery-m/m-spec-functions

 

As for _  ,each is equivalent to

(_)=>

i.e. declaring (the start of) a function where _ is the input argument to the function

Read this excellent article to know more about each and _

https://www.excelguru.ca/blog/2018/01/09/each-keyword-power-query/

Please mark the question solved when done and consider giving a thumbs up if posts are helpful.

Contact me privately for support with any larger-scale BI needs, tutoring, etc.

Cheers 

 

SU18_powerbi_badge

 

Thanks @AlB , that hit the spot!

Helpful resources

Announcements
Feb2025 Sticker Challenge

Join our Community Sticker Challenge 2025

If you love stickers, then you will definitely want to check out our Community Sticker Challenge!

Jan NL Carousel

Fabric Community Update - January 2025

Find out what's new and trending in the Fabric community.

Top Solution Authors
Top Kudoed Authors