JSFiddle - React, Tailwind, and code Playground

by Rahul Desai

JavaScript

var oldArray = [1,2,3];
var newArray = [2,3,4];

        var i = newArray.findIndex(4);
        console.log(i);
/*

update(oldArray, newArray);

function update(oldArry, newArray){
    var resultArray = [];  
    resultArray = oldArray; // copy all old elements first
    
    newArray.forEach(function(element){
        var i = resultArray.findIndex(element);
        console.log(i);
/*        if(resultArray.findIndex(element) == -1){
            resultArray.push(element);
        }*/
  /*  });

}*/