How would I strip something from being encased between colons and retrieve the last one on it

Question

I've been working tirelessly at this pcap analysing script and finally got "somewhere" but now I have the issue of stripping the protocol from the line thats encasing it with colons:

IE:

eth:ethertype:arp

or

eth:ethertype:ip:tcp:ssh

I'm trying to get the last value from each like ssh or arp these objects change in sizes (using tshark pcap - JSON file)

Answer 1

There are multiple ways to do this. You can use .split(":") and then take the last item from the resulting array.

let str = "eth:ethertype:ip:tcp:ssh";

let splits = str.split(":");
console.log(splits[splits.length - 1]);

You can use a regex like:

let str = "eth:ethertype:ip:tcp:ssh";
let regex = /:([^:]+)$/;
let matches = str.match(regex);
if (matches) {
    console.log(matches[1]);
} else {
    console.log("no matches");
}