JavaScript: Replace each character of a given string by the next one in the English alphabet

JavaScript Basic: Exercise-84 with Solution

Replace Characters with Next in Alphabet

Write a JavaScript program to replace each character in a given string with the next in the English alphabet.

Note: ‘a’ will be replace by ‘b’ or ‘z’ would be replaced by ‘a’.

Visual Presentation:

Sample Solution:

JavaScript Code:

// Function to shift each alphabet character in the input string to the next character in the alphabet
function alphabet_char_Shift(str) {
  var all_chars = str.split(""); // Convert the input string into an array of characters
  for(var i = 0; i < all_chars.length; i++) { // Iterate over each character in the array
    var n = all_chars[i].charCodeAt() - 'a'.charCodeAt(); // Calculate the position of the character in the alphabet
    n = (n + 1) % 26; // Shift the position to the next character in the alphabet, considering circular nature
    all_chars[i] = String.fromCharCode(n + 'a'.charCodeAt()); // Update the character with the shifted character
  }
  return all_chars.join(""); // Convert the array of characters back to a string and return
}

// Example usage
console.log(alphabet_char_Shift("abcdxyz"));

Output:

bcdeyza

Explanation:

In the exercise above,

• The input string 'str' is split into an array of individual characters using the "split()" method and stored in the variable 'all_chars'.
• A "for" loop iterates over each character in the 'all_chars' array.
• For each character,
• Its Unicode value is obtained using the "charCodeAt()" method, and the Unicode value of 'a' is subtracted to determine its position in the alphabet.
• The position is shifted to the next character in the alphabet using modular arithmetic ((n + 1) % 26). This ensures that if the character is 'z', it wraps around to 'a'.
• The shifted position is converted back to the corresponding character using "String.fromCharCode()" and 'a''s Unicode value is added back.
• The original character in the array is replaced with the shifted character.
• Finally, the "join()" method is used to join the array of characters back into a single string.

Live Demo:

See the Pen javascript-basic-exercise-84 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

// ES6 version with comments

// Function to shift each alphabet character in a string to the next one in the alphabet
const alphabet_char_Shift = (str) => {
    var all_chars = str.split(""); // Convert the string to an array of characters
    for(var i = 0; i < all_chars.length; i++) {
        var n = all_chars[i].charCodeAt() - 'a'.charCodeAt(); // Get the position of the character in the alphabet
        n = (n + 1) % 26; // Shift to the next character, considering the cyclic nature of the alphabet
        all_chars[i] = String.fromCharCode(n + 'a'.charCodeAt()); // Convert the position back to a character and update the array
    }	
    return all_chars.join(""); // Join the array back to a string and return
};

// Example usage
console.log(alphabet_char_Shift("abcdxyz"));

For more Practice: Solve these Related Problems:

• Write a JavaScript program that replaces each letter in a string with the next letter in the alphabet, wrapping 'z' to 'a' and preserving case.
• Write a JavaScript function that shifts every alphabetic character forward by one, leaving non-letter characters unchanged.
• Write a JavaScript program that transforms a string by incrementing each letter, using char codes and handling edge cases like 'Z' and 'z'.

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