JSFiddle - React, Tailwind, and code Playground

by Avi Algaly

JavaScript

let jsonMsg = {
  type: 'data',
  message_id: 22,
  err: 0
};
let messages = [
  {"type":"command","cmd":"noop","message_id":0},
  {"type":"command","cmd":"noop","message_id":1},
  {"type":"command","cmd":"noop","message_id":2}
]

let msgInx = messages.findIndex((itm) => itm.message_id === jsonMsg.message_id);
console.log(msgInx)