Compare two Arrays and replace Duplicates with values from a third array

Question

var array1 = [\'a\',\'b\',\'c\',\'d\'];
var array2 = [\'a\',\'v\',\'n\',\'d\',\'i\',\'f\'];

var array3 = [\'1\',\'2\',\'3\',\'4\',\'5\',\'6\'];

Just s

Answer 1

Use Array.prototype.reduce to check the duplicates and create a new array - see demo below:

var array1 = ['a','b','c','d'];
var array2 = ['a','v','n','d','i','f'];

var array3 = ['1','2','3','4','5','6'];

var result = array2.reduce(function(p,c,i){
  if(array1.indexOf(c) !== -1) {
     p.push(array3[i]);
  } else {
     p.push(c);
  }
  return p;
},[]);

console.log(result);