Converting alphabets to Greek letters in JavaScript

Converting alphabets to Greek letters in JavaScript requires creating a mapping between English and Greek characters, then replacing each character accordingly.

Character Mapping

First, let's establish the mapping between English and Greek letters:

A=? (Alpha)    B=? (Beta)      D=? (Delta)
E=? (Epsilon)  I=? (Iota)      K=? (Kappa)
N=? (Eta)      O=? (Theta)     P=? (Rho)
R=? (Pi)       T=? (Tau)       U=? (Mu)
V=? (Upsilon)  W=? (Omega)     X=? (Chi)
Y=? (Gamma)

Problem Statement

We need to create a function that converts English letters to their Greek equivalents where mappings exist, while preserving unmapped characters in lowercase.

Input:

const str = 'PLAYING';

Expected Output:

?l????g

Solution

const str = 'PLAYING';

const convertLang = (str) => {
    const map = {
        a: '?', b: '?', d: '?', e: '?',
        i: '?', k: '?', n: '?', o: '?',
        p: '?', r: '?', t: '?', u: '?',
        v: '?', w: '?', x: '?', y: '?'
    };
    
    return str.replace(/./g, char => {
        const lowerChar = char.toLowerCase();
        if (map[lowerChar]) {
            return map[lowerChar];
        }
        return lowerChar;
    });
};

console.log(convertLang(str));

?l????g

How It Works

The function uses the replace() method with a regular expression /./g to match every character. For each character:

• Convert to lowercase using toLowerCase()
• Check if a Greek mapping exists in the map object
• Return the Greek letter if found, otherwise return the lowercase English letter

Testing with Multiple Examples

const convertLang = (str) => {
    const map = {
        a: '?', b: '?', d: '?', e: '?',
        i: '?', k: '?', n: '?', o: '?',
        p: '?', r: '?', t: '?', u: '?',
        v: '?', w: '?', x: '?', y: '?'
    };
    
    return str.replace(/./g, char => {
        const lowerChar = char.toLowerCase();
        return map[lowerChar] || lowerChar;
    });
};

// Test cases
console.log("PLAYING ?", convertLang("PLAYING"));
console.log("BETA ?", convertLang("BETA"));
console.log("HELLO ?", convertLang("HELLO"));
console.log("PYTHON ?", convertLang("PYTHON"));

PLAYING ? ?l????g
BETA ? ????
HELLO ? h?llo
PYTHON ? ???h??

Conclusion

This solution efficiently converts English letters to Greek equivalents using object mapping and regular expressions. Characters without Greek mappings are converted to lowercase and preserved in the output.