Swapping letter with succeeding alphabet in JavaScript

We are required to write a JavaScript function that takes in a string and changes every letter of the string from the English alphabets to its succeeding element.

For example: If the string is −

const str = 'how are you';

Output

Then the output should be −

const output = 'ipx bsf zpv'

Therefore, let’s write the code for this function −

Example

The code for this will be −

const str = 'how are you'; const isAlpha = code => (code >= 65 && code <= 90) || (code >= 97 && code <= 122); const isLast = code => code === 90 || code === 122; const nextLetterString = str => {    const strArr = str.split('');    return strArr.reduce((acc, val) => {       const code = val.charCodeAt(0);       if(!isAlpha(code)){          return acc+val;       };       if(isLast(code)){          return acc+String.fromCharCode(code-25);       };       return acc+String.fromCharCode(code+1);    }, ''); }; console.log(nextLetterString(str));

The output in the console will be −

ipx bsf zpv