For if statement in Function Block, variable remains local

Please review this code:

let senState_msg;
if (msg.payload==="On") {
let senState_msg={payload:"Sys08: ASE"};
} else {
let senState_msg={payload:"Sys07: SSD"};

return senState_msg;

I've declared the variable senState_msg prior to the if-block, but the variable of the same name within the if-block remains local. How do I get the value set in the if-block outside?

Chatted with @xytsrm he found an answer and I thought it was a good question for future readers so opened to allow a response.

here is the chat

Hi, That is a good question. I take it you figured out not to declare let again inside the if block.

Yes, exactly. I don't use Java script too often, I'm far more familiar with Python where there are no explicit declarations. Also, I learned that if you want a variable to be global outside the if-block you need to declare it before the if-block. There was an archaic programming language that I used decades ago where you needed to use "let" all the time, for declarations & assignments; I think that was blinding me to the "let" statements in the if-block.

The funny thing is I summited that code sample to ChatGPT, before I made the declaration prior to the if-block. ChatGPT said the code looked ok, but I needed to make the declaration before the if-block. BUT, then it reprinted my code WITHOUT the "let" in the if-block. Can you believe I still missed the removal of the "let"; it never explicitly said you need to remove the "let" - lol.

Regarding leaving the question on the forum as a "learning experience" you right I probably should have, but I was so embarrassed by what I came to see as an obvious error, I hastily deleted it; I'll consider un-deleting it.

If you want a global var declare it with var name;

Mistakes are easy to overlook we have all been there

This is a great community and I would not worry about embarrasment, there are no stupid questions when learning.

Thanks for the encouragement - lol

Interestingly, I found the either let, or var works, but you're right var is preferred. I had tried the 'var' but it made no difference to the error, but that was before I realized the real error; the 'let' in the if-block.

var is global and will be available any where
let is confined in the { } block only or global if defined outside any { }

in that order
const means the var will not change, object defined const must always be an object but you can redefine the properties.

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