Rename cells in Attribute Table to 'XXX.$ID'

Question

I feel like this should be easy to answer, but I can't get it to work for me. I need to edit the attribute table of a .gpx file before I load it into my GPS, in order to label the points. I can rename each point with $ID, but I have several files and want to be able to distinguish between them. I would like to be able to name them something like "500m.1" "500m.2"... "1km.1" "1km.2"... etc.

I can use the expression 500+$ID to give me "501" "502" etc. but that will become difficult to read for some of the files. How can I combine text with $ID in a single cell? All my attempts so far result in 'Expression is invalid'.

Answer 1

I just didn't know what I needed to search for. I've now discovered the concatenate option under "String > concat". To solve my problem I used the expression; concat('500m.',$ID)