JSFiddle - React, Tailwind, and code Playground

by saidulu401

JavaScript

let arr = [1,4,7,9,10,2,3];
//return missing numbers from array
arr.sort((a,b)=>a-b);
//console.log(arr,'arr');
let previousEl =0;
//const arr2= 
const arr3 = []
arr.forEach(e=>{
	if(e-previousEl>1){
  	for(let i=previousEl+1;i<e;i++){
    	arr3.push(i);
    }
  	//arr3.push(...new Array(e-previousEl).fill(e+1))
   
  }
  //console.log(e,previousEl,'e,previousEl')
   previousEl = e;
  
})
console.log(arr3,'missing array ')