JavaScript - How do I convert unicode characters? English numbers to Persian numbers

Question

I'm building a software that takes integers from users and does some calculations and then outputs the result. The thing is that I want to take users numbers using English numbers(0, 1, 2, etc.) and I want to present the numbers using Persian numbers(like Arabic) in the output. I've read some topics on Unicode conversion and things like replace() and charCodeAt() but I can't understand the code.

Here's a piece of code.(It converts Persian numbers into English numbers but I want to do the opposite.)

 var yas ="٠١٢٣٤٥٦٧٨٩";
 yas = Number(yas.replace(/[٠١٢٣٤٥٦٧٨٩]/g, function (d) {
     return d.charCodeAt(0) - 1632;                
     }).replace(/[۰۱۲۳۴۵۶۷۸۹]/g, function (d) { return d.charCodeAt(0) - 1776; })
 );

user_157247 · Answer

That Persian-to-English script seems unnecessarily complicated, which makes me wonder if I'm missing something.

Basically, with such a limited data set, the simplest thing is to give yourself a map either way:

// The "Persian" here aren't just Persian, nor are the English just English.
// Both numeral sets are used in multiple languages...

// One time setup
var persian ="٠١٢٣٤٥٦٧٨٩";
var mapPtoE = Object.create(null);
var mapEtoP = Object.create(null);
persian.split("").forEach(function(glyph, index) {
  mapPtoE[glyph] = index;
  mapEtoP[index] = glyph;
});
// Convert one char "Persion" => "English"
function charPtoE(ch) {
  return mapPtoE[ch] || ch;
}
// Convert one char "English" => "Persion"
function charEtoP(ch) {
  return mapEtoP[ch] || ch;
}
// Convert the "Persian" digits in a string to "English"
function strPToE(s) {
  return s.replace(/[٠١٢٣٤٥٦٧٨٩]/g, charPtoE);
}
// Convert the "English" digits in a string to "Persian"
function strEToP(s) {
  return s.replace(/\d/g, charEtoP);
}

// Demonstrate converting "Persian" to "English"
console.log("Test A ٠١٢٣", "=>", strPToE("Test A ٠١٢٣"));
console.log("Test B ٦٥٤", "=>",  strPToE("Test B ٦٥٤"));
console.log("Test C ٧٨٩", "=>",  strPToE("Test C ٧٨٩"));

// Demonstrate converting "English" to "Persian"
console.log("Test A 0123", "=>", strEToP("Test A 0123"));
console.log("Test B 654", "=>",  strEToP("Test B 654"));
console.log("Test C 789", "=>",  strEToP("Test C 789"));

From your question it looks like there can be more than one form for 4 and 6 (pardon my ignorance); if so, you'll want to adjust the above to handle that in the "Persian" to "English" conversion, and pick one to use going the other way.

user_646887 · Answer

It looks like the code you posted handles both Arabic and Persian digits. To convert back you can use either

var yas ="1234567890";

// To Arabic digits
yas = yas.replace(/[0-9]/g, function (d) {
    return d.charCodeAt(0) + 1632;    // 1632 == '٠' - '0'           
});

or

// To Persian digits
yas = yas.replace(/[0-9]/g, function (d) {
    return d.charCodeAt(0) + 1776;  // 1776 == '۰' - '0' 
});

depending on which set you want to use.

The numbers 1632 and 1776 is the difference between the codepoints for regular digits and the codepoints for the Arabic and Persian digits.

JavaScript - How do I convert unicode characters? English numbers to Persian numbers

2 Answers