How do I replace all letters in a string with another letter/special character? [duplicate]

Question

I am trying to make a small node application that lets me convert text to double-struck "letters". I am fairly new to JavaScript, and I was wondering what the best way to do this?

I could use: string.replace("A", doublestruck.uppercase.A) (see below) 62 (26 uppercase, 26 lowercase, 10 number), but I feel like there is definitely a better way to do this.

// specialcharacters.js
const doubleStruckUpper = {
        A: "𝔸", B: "𝔹", C: "ℂ", D: "𝔻", E: "𝔼",
        F: "𝔽", G: "𝔾", H: "ℍ", I: "𝕀", J: "𝕁",
        K: "𝕂", L: "𝕃", M: "𝕄", N: "ℕ", O: "𝕆",
        P: "ℙ", Q: "ℚ", R: "ℝ", S: "𝕊", T: "𝕋",
        U: "𝕌", V: "𝕍", W: "𝕎", X: "𝕏", Y: "𝕐",
        Z: "ℤ"
    };
const doubleStruckLower = { ... };
const doubleStruckNumbers = { ... };

module.exports.doubleStruck = {
    uppercase: doubleStruckUpper,
    lowercase: doubleStruckLower,
    numbers: doubleStruckNumbers,
};

// index.js

const { doubleStruck } = require("./specialcharacters");

var string = "Change this to double-struck characters";

string
    .replace("A", doubleStruck.uppercase.A)
    .replace("B", doubleStruck.uppercase.B)
    // and so on

This would work, but it would have to be so long and there is probably a better way to do this.

Thanks in advance!

Answer 1

.replace lets you use a function:

const doubleStruckUpper = {
        A: "𝔸", B: "𝔹", C: "ℂ", D: "𝔻", E: "𝔼",
        F: "𝔽", G: "𝔾", H: "ℍ", I: "𝕀", J: "𝕁",
        K: "𝕂", L: "𝕃", M: "𝕄", N: "ℕ", O: "𝕆",
        P: "ℙ", Q: "ℚ", R: "ℝ", S: "𝕊", T: "𝕋",
        U: "𝕌", V: "𝕍", W: "𝕎", X: "𝕏", Y: "𝕐",
        Z: "ℤ"
    };

var string = "CHANGE THIS TO DOUBLE STRUCK LETTERS";

var result = string.replace(/[A-Z]/g, matchedLetter => doubleStruckUpper[matchedLetter]);

console.log(result);

Combined with a regex, you can find and match all desired characters and replace them, one by one, with the desired character. Since you've already created character maps, this should be a fairly fast and easy process, though I would recommend combining your character maps into a single map to make it faster and simpler.