JSFiddle - React, Tailwind, and code Playground

JavaScript

var arrayOfObjs = [{
  "ob1": "test1"
}, {
  "ob2": "test1"
}, {
  "ob1": "test3"
}];

function FindIndex(key) {
  var rx = /\{.*?\}/;
  var arr = [];
  var str = JSON.stringify(arrayOfObjs);
  for (i = 0; i < arrayOfObjs.length; i++) {
    arr.push(str.match(rx)[0]);
    str = str.replace(rx, '');
  }
  var Index = arr.indexOf(JSON.stringify(key));
  alert(Index);
}

FindIndex({"ob2": "test1"});