Replace last letters in array of strings Javascript

Question

I need to do as follows:

I've got an array of strings containing last names. Some of them ends with letter 'i'.

manLastNames = ["testowski","bucz","idzikowski","gosz"];

I need to make a function which will iterate over this array of strings and if there is an element ending with 'i', I need to replace this 'i' for 'a', otherwise just leave string as it is.

At the end I want to have another array where all last 'i's are replaced with 'a's.

womanLastNames = ["testowska","bucz","idzikowska","gosz"];

This is what I have now, but Im pretty sure that it start being crap at some point

    var rep = function() {
  var manLastNames = ["testowski","bucz","idzkowski","gosz"];
  var womanLastNames = new Array(4);


  for (var i=0; i<manLastNames.length; i++) {
    var lastName = manLastNames[i];
    if (lastName.substr(lastName.length - 1, 1) == 'i') {
        lastName = lastName.substr(0, lastName.length - 1) + 'a';
  }
  }

  for (var i=0; i<womanLastNames.length; i++) {
    womanLastNames[i] = lastName[i];

  }

  console.log(womanLastNames);
}
rep();

Answer 1

Here is solution

var rep = function() {
  var manLastNames = ["testowski","bucz","idzkowski","gosz"];
  var womanLastNames =[];

  for (var i=0; i<manLastNames.length; i++) {
    var lastName = manLastNames[i];
    if (lastName.charAt(lastName.length - 1) == 'i') {
        lastName = lastName.substr(0, lastName.length - 1) + 'a';
   }
   womanLastNames.push(lastName);
  }
  console.log(womanLastNames);
}
rep();

Another solution is to use .map method like this, using a callback function:

var manLastNames = ["testowski","bucz","idzikowski","gosz"];
function mapNames(item){
   return item[item.length-1]=='i' ? item.substr(0, item.length-1) + "a" : item;
}
console.log(manLastNames.map(mapNames));