TypeScript - convert decimal number to bin, oct, hex, etc. (to any base system)

const dec: number = 123; // decinal number

const base: number = 16; // to base 16 number - to hexadecinal number

​

const hex: string = dec.toString(base);

​

console.log(hex); // 7b

console.log(hex.toUpperCase()); // 7B

const ALPHABET: string = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';

​

const convertBase = (dec: number, base: number): string => {

    // add to ALPHABET more characters to get greater base

    if (base > ALPHABET.length) {

        throw new Error('Maximal supported base value is ' + ALPHABET.length + '.');

    }

    let result = '';

    while (true) {

        const quotient = Math.floor(dec / base);

        const index = dec - base * quotient;

        result = ALPHABET[index] + result;

        if (quotient < 1) {

            break;

        }

        dec = quotient;

    }

    return result;

};

​

​

// Usage example:

​

//                      dec  base

console.log(convertBase(  0,  2));  // 0       (base 2)   <--- bin

console.log(convertBase(123,  2));  // 1111011 (base 2)   <--- bin

console.log(convertBase(123,  3));  // 11120   (base 3)

console.log(convertBase(123,  4));  // 1323    (base 4)

console.log(convertBase(123,  5));  // 443     (base 5)

console.log(convertBase(123,  6));  // 323     (base 6)

console.log(convertBase(123,  7));  // 234     (base 7)

console.log(convertBase(123,  8));  // 173     (base 8)   <--- oct

console.log(convertBase(123, 10));  // 123     (base 10)  <--- dec / identity

console.log(convertBase(123, 16));  // 7B      (base 16)  <--- hex

console.log(convertBase(123, 32));  // 7R      (base 32)

console.log(convertBase(123, 36));  // 3F      (base 36)

console.log(convertBase( 36, 36));  // 10      (base 36)

0

1111011

11120

1323

443

323

234

173

123

7B

3R

3F

10