为什么我的解密功能不起作用

Question

我创建了一个函数来加密和解密消息。加密工作正常。但是当我尝试记录加密的CCD_ 1时，它只记录CCD_。

const chars = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz".split("");
const numbs = "0123456789".split("");
const symbols = "!@#$%^&*()_+-=[]{}|;':,./<>?" ".split("");
function encrypt(message) {
message = message.split("")
var output = []
message.forEach(element => {
if (chars.includes(element)) {
output.push("c" + chars.indexOf(element))
} else if (numbs.includes(element)) {
output.push("n" + numbs.indexOf(element))
} else if (symbols.includes(element)) {
output.push("s" + symbols.indexOf(element))
} else {
console.log(element)
throw new Error(`Unknown character`)
}
});
return output.join("")
}
function decrypt(message) {
message = message.split("");
var output = [];
var prevDeter;
var prevNumbs = [];
message.forEach(element => {
if (element == "c") {
prevDeter = "c"
if (prevNumbs.length > 0) {
output.push(chars[parseInt(prevNumbs.join(""))])
}
} else if (element == "n") {
prevDeter = "n"
if (prevNumbs.length > 0) {
output.push(numbs[parseInt(prevNumbs.join(""))])
}
} else if (element == "s") {
prevDeter = "s"
if (prevNumbs.length > 0) {
output.push(symbols[parseInt(prevNumbs.join(""))])
}
} else {
prevNumbs.push(element)
}
});
return output.join("")
}
//expected to log Hello World! but logs H and when starting the message with a symbol or number it just logs nothing
console.log(decrypt(encrypt("Hello World!")))

修复了它，我编辑了编码系统，在字符之间放置了一个-，解码系统只在-处拆分消息，并检查元素是否以c n或s开头。然后我只使用子字符串来获取数字并解密

const chars = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz".split("");
const numbs = "0123456789".split("");
const symbols = "!@#$%^&*()_+-=[]{}|;':,./<>?" ".split("");
function encrypt(message) {
message = message.split("");
var output = [];
message.forEach(element => {
if(chars.includes(element)) {
output.push("-c" + chars.indexOf(element));
}else if(numbs.includes(element)) {
output.push("-n" + numbs.indexOf(element));
}else if(symbols.includes(element)) {
output.push("-s" + symbols.indexOf(element));
}else{
console.log(element);
throw new Error(`Unknown character`);
};
});
return output.join("");
};
function decrypt(message) {
message = message.split("-");
console.log(message)
var output = [];
message.forEach(element => {
if(element.startsWith("c")) {
output.push(chars[element.substring(1)]);
}else if(element.startsWith("n")) {
output.push(numbs[element.substring(1)]);
}else if(element.startsWith("s")) {
output.push(symbols[element.substring(1)]);
}else if(element.length < 1){

}else{
throw new Error(`Invalid message`);
}
});
return output.join("");
};
console.log(decrypt(encrypt("Hello World!")));

Answer 1

您需要根据集合/索引对拆分编码的字符串。这对于在c、n或s之前使用前瞻性正则表达式和拆分非常容易。/(?=[cns])/

const chars = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz".split("");
const numbs = "0123456789".split("");
const symbols = "!@#$%^&*()_+-=[]{}|;':,./<>?" ".split("");
function encrypt(message) {
message = message.split("")
var output = []
message.forEach(element => {
if (chars.includes(element)) {
output.push("c" + chars.indexOf(element))
} else if (numbs.includes(element)) {
output.push("n" + numbs.indexOf(element))
} else if (symbols.includes(element)) {
output.push("s" + symbols.indexOf(element))
} else {
console.log(element)
throw new Error(`Unknown character`)
}
});
return output.join("")
}
function decrypt(message) {
message = message.split(/(?=[cns])/);
var output = [];
message.forEach(element => {
let set;
switch(element[0]){
case 'c':
set = chars;
break;
case 'n':
set = numbs;
break;
case 's':
set = symbols;
break;
}
const index = parseInt(element.substring(1));
output.push(set[index]);
});
return output.join('');
}
const encrypted = encrypt("Hello World!");
console.log(encrypted);
//expected to log Hello World! but logs H and when starting the message with a symbol or number it just logs nothing
console.log(decrypt(encrypted));