Substr in function

Hello all,

I thought I could put a substring in a function but it doesn't work a priori, what is my mistake please?

I have this error => TypeError: Data.substr is not a function

Below my (simple) function :

let Data = msg.payload;
let totalLeaks = (Data.substr(6,6));
let lastleakduration = (Data.substr(12,6));
msg.payload = {
    leaks : totalLeaks,
    duration : lastleakduration
return msg;

Hi @bpi2008

substr is a function only available on String objects.

This error suggests the msg.payload you are passing this function is not a String.

Can you wire in a Debug node in parallel to see exactly what msg.payload you are passing into the function?

Hi Knolleray,

decoded_payload: object
BAT_V: 3.144
MOD: 2

I have changed simply my function and i's ok now by :

var duration = msg.payload.uplink_message.decoded_payload.WATER_LEAK_TIMES;
msg.payload = duration;
return msg;

I'm very interesting to test "substr" for other functions.

Many thanks for all. Bernard

For the record, you should be using substring(), substr has been deprecated.

very good thanks Colin

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