使用 JavaScript 的凯撒密码答案

【问题标题】：Caesar cipher with JavaScript使用 JavaScript 的凯撒密码
【发布时间】：2022-11-28 03:08:31
【问题描述】：

我检查了具有不同代码变体的不同网站，但找不到合适的答案。我需要创建 2 个函数，其中： -1st 函数将使用密钥加密给定的消息，该密钥是字符串；例如如果 Message=hello 且 key=123（因此键将为 1、2、3），输出应为“igomq” -2nd 将破译我已经编写了代码，但这仅在密钥为“123”时有效。如何改进？

function cipher(message, key) {
    const arrOfKeys = key.split("")
    const cipheredMessage = []
    let newLettersArr = []
    for (let i = 0; i < message.length; i++) {
        let remain = i % arrOfKeys.length
        if (remain >= 0) {
            let newLetter = message.charCodeAt(i) + (remain + 1)
            newLettersArr.push(newLetter)
        }
    }
    newLettersArr.forEach((letter) => {
        let cipheredLetter = String.fromCharCode(letter)
        cipheredMessage.push(cipheredLetter)
    })
    return cipheredMessage
}

function deCipher(message, key) {
    const arrOfKeys = key.split("")
    const cipheredMessage = []
    let newLettersArr = []
    for (let i = 0; i < message.length; i++) {
        let remain = i % arrOfKeys.length
        if (remain >= 0) {
            let newLetter = message.charCodeAt(i) - (remain + 1)
            newLettersArr.push(newLetter)
        }
    }
    newLettersArr.forEach((letter) => {
        let cipheredLetter = String.fromCharCode(letter)
        cipheredMessage.push(cipheredLetter)
    })
    return cipheredMessage
}

console.log(cipher("hello", "123"))
console.log(deCipher("igomq", "123"))

【问题讨论】：

标签： javascript arrays caesar-cipher

【解决方案1】：

看起来您需要从 arrOfKeys 获取值以递增/递减 char 代码。

function cipher(message, key) {
    const arrOfKeys = key.split("");
    const cipheredMessage = [];
    let newLettersArr = [];
    for (let i = 0; i < message.length; i++) {
        let remain = i % arrOfKeys.length;
        if (remain >= 0) {
            let newLetter = message.charCodeAt(i) + +arrOfKeys[remain];
            newLettersArr.push(newLetter);
        }
    }
    newLettersArr.forEach((letter) => {
        let cipheredLetter = String.fromCharCode(letter);
        cipheredMessage.push(cipheredLetter);
    });
    return cipheredMessage;
}

function deCipher(message, key) {
    const arrOfKeys = key.split("");
    const cipheredMessage = [];
    let newLettersArr = [];
    for (let i = 0; i < message.length; i++) {
        let remain = i % arrOfKeys.length;
        if (remain >= 0) {
            let newLetter = message.charCodeAt(i) - arrOfKeys[remain];
            newLettersArr.push(newLetter);
        }
    }
    newLettersArr.forEach((letter) => {
        let cipheredLetter = String.fromCharCode(letter);
        cipheredMessage.push(cipheredLetter);
    });
    return cipheredMessage;
}

console.log(cipher("hello", "5123"))
console.log(deCipher("mfnot", "5123"))

【讨论】：