find missing number from array

by Pritesh Patel

JavaScript

//let a = [1,2,3,4,6]

/* function missingNum(arr){
  let sortArr = arr.sort((a,b)=> a-b);
  console.log(sortArr);
  let f = [...new Set(sortArr)];
  console.log(f);
  
  for (let i = 1; i < f.length; i++) {
    if ((f[i] !== f[i-1] + 1)) {
      console.log(f[i]-1); 
    } else {
      console.log("true");
    }
}
}
missingNum([1,3,2,4,4,6,10]); */

function missingNum(num,n){
	let rest = [];
  
  for(let i=1; i<=n; i++){
  	if(num.includes(i) == false){
    	rest.push(i);
    }
  }
  return console.log(rest);
}
missingNum([1,3,2,4,4,10],20);