Replace Umlauts in both directions

Question

I am trying to replace Umlauts in both directions. I managed to replace Umlauts in one direction. For example, a string has an ö (Björn) than oe (Bjoern) should be written. This is the code I used:

umlauts = {"ä":"ae", "ü":"ue", "ö":"oe"}

replaceUmlaute = function(s) {
return s.replace(/[äöüß]/g, function($0) {
 return umlauts[$0] })
}

How could I change the code in order to make it dynamic so the umlaut would be replaced in both ways Björn -> Bjoern or Bjoern->Björn. I need a function that takes a string and checks the umlauts. If its an ö then switch to oe and if its an oe then switch to ö. Thanks!

why can't you just add keys going in the other directions to the umlaut variable, and update your regex to match those keys? — driusan, Feb 22 '16 at 15:43
Please watch out that at least for the german language the reverse direction (i.e. "oe" => "ö" etc.) is not necessarily grammatically correct. For example "Quetschung" => "Qütschung", "kongruent" => "kongrünt" etc. — Entimon, Feb 01 '21 at 16:35

mplungjan · Accepted Answer · 2020-10-17T07:14:06.243

Using one function to go both ways like this:

var str = "Bjoern, Joern, und ein Schloss am Woerthersee, Suess, Bjoern, Joern, und ein Schloss am Woerthersee, Suess";
var mapObj = {
   "ae":"ä",
   "oe":"ö",
   "ue":"ü",
   "ss":"ß",
   "ä":"ae",
   "ö":"oe",
   "ü":"ue",
   "ß":"ss"
}, reg1 = /ä|ö|ü|ß/gi, reg2 = /ae|oe|ue|ss/gi;

function conv(str) {
  var reg = /ä|ö|ü|ß/i.test(str)?reg1:reg2;
  return str.replace(reg, function(matched, offset, s){
    return mapObj[matched];
  });
}
str = conv(str);
document.body.innerHTML += '<br/>1:'+str;
str = conv(str);
document.body.innerHTML += '<br/>2:'+str;

Initially a duplicate of Replace multiple strings with multiple other strings.

In your case:

var str = "Bjoern, Joern, und ein Schloss am Woerthersee.";
var mapObj1 = {
   "ae":"ä",
   "oe":"ö",
   "ue":"ü",
   "ss":"ß"
};
var mapObj2 = {
   "ä":"ae",
   "ö":"oe",
   "ü":"ue",
   "ß":"ss"
};

str = str.replace(/ae|oe|ue|ss/gi, function(matched){
  return mapObj1[matched];
});
document.write(str)

str = str.replace(/ä|ö|ü|ß/gi, function(matched){
  return mapObj2[matched];
});

document.write('<br/>'+str)

Thanks. But would it be possible to do this in one function? So I could just write a string and it will always switch opposite? This is what I am looking for. — clde, Feb 22 '16 at 15:59

Replace Umlauts in both directions

1 Answers1