Question for how to get publickey and privatekey & how to verify those key?

[johnnyji-dev]

Hi, I'm using polkadotjs. When I create a wallet, I create a mnemonic first.
After generating the mnemonic, I tried to get some information(address, publickey, privatekey) like below source code.
Plz check these below source code and result, and give me some feedback which one is incorrect. If incorrect how can I modify that?

import { mnemonicGenerate, cryptoWaitReady, encodeAddress, mnemonicToMiniSecret, randomAsHex, ed25519PairFromSeed } from '@polkadot/util-crypto';
import { Keyring } from '@polkadot/keyring';
import { u8aToHex, stringToU8a, hexToU8a, u8aToString } from '@polkadot/util';

const create = async (limit) => {
let walletList = [];
const keyring = new Keyring({ type: 'sr25519', ss58Format: 5 });

for (let i = 0; i < limit; i++) {
    const mnemonic = mnemonicGenerate(); // Creates a valid mnemonic string using using [BIP39]
    await cryptoWaitReady();

    const krpair = keyring.addFromMnemonic(mnemonic, { astar: i }, 'sr25519');
    console.log('mnemonic : ${mnemonic}`);
    const address = krpair.address;
    console.log(`address : ${address}`);
    const publicKey = krpair.publicKey;
    console.log(`publicKey : ${u8aToHex(publicKey)}`);
    const privateKey = mnemonicToMiniSecret(mnemonic);
    console.log(`privateKey : ${u8aToHex(privateKey)}`);

    const edPair = ed25519PairFromSeed(privateKey);

    // console.log(`publicKey : ${u8aToHex(edPair.publicKey)}`);
    console.log(`secretKey : ${u8aToHex(edPair.secretKey)}`);
}

}

create(1);

Additionally, How can I get "mnemonic" from secretKey?