一种常见的现代用法是ROT13密码,其中字母的值移动了13位。因此是'A'↔'N', 'B'↔'O',以此类推。
function rot13(str) {
let newStr="";
let upperAlph=["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","W","X","Y","Z"]
let rotAlph=["N","O","P","Q","R","S","T","U","V","W","X","Y","Z","A","B","C","D","E","F","G","H","I","J","K","L","M"];
for(let i=0; i<str.length; i++){
let letter=str[i];
let letTest=/[A-Z]/g;
if(letTest.test(letter)){
let indexOfLetter=upperAlph.indexOf(letter);
let newLetter=rotAlph[indexOfLetter];
newStr+newLetter;
}
else{
newStr+letter;
}
}
return newStr;
}
console.log(rot13("SERR PBQR PNZC"));
修复你的代码,看看第12行和第15行,我相信:
function rot13(str) {
let newStr="";
let upperAlph=["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","W","X","Y","Z"]
let rotAlph=["N","O","P","Q","R","S","T","U","V","W","X","Y","Z","A","B","C","D","E","F","G","H","I","J","K","L","M"];
for(let i=0; i<str.length; i++){
let letter=str[i];
let letTest=/[A-Z]/g;
if(letTest.test(letter)){
let indexOfLetter=upperAlph.indexOf(letter);
let newLetter=rotAlph[indexOfLetter];
newStr += newLetter;
}
else{
newStr += letter;
}
}
return newStr;
}
console.log(rot13("SERR PBQR PNZC"));
我也会使用映射类型的对象,而不是两个数组:
alphMap = {A: 'N', B: 'O', C: 'P', ..., Z: 'M'};
你可以像这样找到你的替代字母:
let newLetter = alphMap[letter];
不需要匹配索引
您错过了upperAlph的U和V
function rot13(str) {
let newStr="";
let upperAlph=["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"]
let rotAlph=["N","O","P","Q","R","S","T","U","V","W","X","Y","Z","A","B","C","D","E","F","G","H","I","J","K","L","M"];
for(let i=0; i<str.length; i++){
let letter=str[i];
let letTest=/[A-Z]/g;
if(letTest.test(letter)){
let indexOfLetter=upperAlph.indexOf(letter);
let newLetter=rotAlph[indexOfLetter];
newStr += newLetter;
}
else{
newStr += letter;
}
}
return newStr;
}