JavaScript: Replace every character in a given string with the character following it in the alphabet

JavaScript Basic: Exercise-49 with Solution

Write a JavaScript program to replace every character in a given string with the character following it in the alphabet.

Visual Presentation:

Sample Solution:

JavaScript Code:

// Define a function named LetterChanges with parameter text
function LetterChanges(text) {
    // Initialize an array by splitting the input text into individual characters
    var s = text.split('');

    // Iterate through each character in the array
    for (var i = 0; i < s.length; i++) {
        // Caesar cipher: Shift each character by one position in the alphabet
        switch(s[i]) {
            case ' ':
                break;
            case 'z':
                s[i] = 'a';
                break;
            case 'Z': 
                s[i] = 'A';
                break;
            default:
                s[i] = String.fromCharCode(1 + s[i].charCodeAt(0));
        }

        // Convert vowels to uppercase
        switch(s[i]) {
            case 'a': case 'e': case 'i': case 'o': case 'u':
                s[i] = s[i].toUpperCase();
        }
    }

    // Join the modified characters back into a string and return the result
    return s.join('');
}

// Log the result of calling LetterChanges with the argument "PYTHON" to the console
console.log(LetterChanges("PYTHON"));

// Log the result of calling LetterChanges with the argument "W3R" to the console
console.log(LetterChanges("W3R"));

// Log the result of calling LetterChanges with the argument "php" to the console
console.log(LetterChanges("php"));

Output:

QZUIPO
X4S
qIq

Live Demo:

See the Pen JavaScript - Replace every character in a given string with the character following it in the alphabet - basic-ex-49 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

// Define a function named LetterChanges with parameter text
const LetterChanges = (text) => {
    // Split the input text into an array of characters
    let s = text.split('');

    // Iterate through each character in the array
    for (let i = 0; i < s.length; i++) {
        // Caesar cipher
        switch (s[i]) {
            case ' ':
                break;
            case 'z':
                s[i] = 'a';
                break;
            case 'Z':
                s[i] = 'A';
                break;
            default:
                s[i] = String.fromCharCode(1 + s[i].charCodeAt(0));
        }

        // Upper-case vowels
        switch (s[i]) {
            case 'a':
            case 'e':
            case 'i':
            case 'o':
            case 'u':
                s[i] = s[i].toUpperCase();
        }
    }

    // Join the modified array back into a string and return it
    return s.join('');
};

// Log the result of calling LetterChanges with the argument "PYTHON" to the console
console.log(LetterChanges("PYTHON"));

// Log the result of calling LetterChanges with the argument "W3R" to the console
console.log(LetterChanges("W3R"));

// Log the result of calling LetterChanges with the argument "php" to the console
console.log(LetterChanges("php"));

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