1. Using a for loop:
Explanation: Iterate through the string in reverse and build a new reversed string.
function reverseString(str) {
let reversed = "";
for (let i = str.length - 1; i >= 0; i--) {
reversed += str[i];
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // olleH2. Using the split(), reverse(), and join() methods:
Split the string into an array, reverse the array, and then join it back to a string.
function reverseString(str) {
return str.split("").reverse().join("");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // olleH3. Using recursion:
Recursively swap the first and last characters of the string until it's reversed.
function reverseString(str) {
if (str === "") return "";
else return reverseString(str.substr(1)) + str[0];
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"4. Using the reduce() method:
Use the reduce() method to build the reversed string.
function reverseString(str) {
return str.split("").reduce((reversed, char) => char + reversed, "");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"
5. Using the map() and reverse() methods:
Use the map() method to create an array of reversed characters and then join them.
function reverseString(str) {
return str.split("").map((char, index, arr) => arr[arr.length - 1 - index]).join("");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"6. Using the substring() method:
Build the reversed string by taking substrings from the original string in reverse order.
function reverseString(str) {
let reversed = "";
for (let i = 0; i < str.length; i++) {
reversed = str.charAt(i) + reversed;
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"7. Using the split() method with a spread operator:
Convert the string to an array and use the spread operator to reverse it.
function reverseString(str) {
return [...str].reverse().join("");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"8. Using the Array.from() method:
Use the Array.from() method to create an array from the string and then reverse it.
function reverseString(str) {
return Array.from(str).reverse().join("");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"9. Using the Array.from() method with reduceRight():
Convert the string to an array, use reduceRight() to reverse it and join the characters.
function reverseString(str) {
return Array.from(str).reduceRight((reversed, char) => reversed + char, "");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"10. Using a while loop:
Create a reversed string character by character using a while loop.
function reverseString(str) {
let i = str.length - 1;
let reversed = "";
while (i >= 0) {
reversed += str[i];
i--;
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"11. Using the XOR swap algorithm:
Swap characters using the XOR operation.
function reverseString(str) {
let arr = str.split("");
let start = 0;
let end = str.length - 1;
while (start < end) {
arr[start] = String.fromCharCode(arr[start].charCodeAt(0) ^ arr[end].charCodeAt(0));
arr[end] = String.fromCharCode(arr[start].charCodeAt(0) ^ arr[end].charCodeAt(0));
arr[start] = String.fromCharCode(arr[start].charCodeAt(0) ^ arr[end].charCodeAt(0));
start++;
end--;
}
return arr.join("");
}
const reversedString = reverseString("Hello");
12. Using a for...of loop:
Iterate over the characters of the string using a for...of loop.
function reverseString(str) {
let reversed = "";
for (const char of str) {
reversed = char + reversed;
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"13. Using charAt() and a for loop:
Iterate through the string using a for loop and append characters using charAt().
function reverseString(str) {
let reversed = "";
for (let i = 0; i < str.length; i++) {
reversed = str.charAt(i) + reversed;
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"14. Using recursion and substring():
Recursively shorten the string using substring() and append the first character.
function reverseString(str) {
let reversed = "";
for (let i = 0; i < str.length; i++) {
reversed = str.charAt(i) + reversed;
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"15. Using a for...in loop:
Iterate through the string using a for...in loop (not recommended for strings).
function reverseString(str) {
let reversed = "";
for (let index in str) {
reversed = str[index] + reversed;
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"16. Using a do...while loop:
Build the reversed string using a do...while loop.
function reverseString(str) {
let i = str.length - 1;
let reversed = "";
do {
reversed += str[i];
i--;
} while (i >= 0);
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"17. Using the split() method and a for loop:
Split the string into an array and use a for loop to reverse it.
function reverseString(str) {
const arr = str.split("");
let reversed = "";
for (let i = arr.length - 1; i >= 0; i--) {
reversed += arr[i];
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"18. Using a stack data structure:
Push each character onto a stack and then pop them to build the reversed string.
function reverseString(str) {
const stack = [];
for (const char of str) {
stack.push(char);
}
let reversed = "";
while (stack.length > 0) {
reversed += stack.pop();
}
return reversed;
}
const reversedString = reverseString("Hello");
19. Using String.prototype.slice() with a for loop:
Iterate through the string in reverse order using slice() to extract characters.
function reverseString(str) {
let reversed = "";
for (let i = str.length - 1; i >= 0; i--) {
reversed += str.slice(i, i + 1);
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"20. Using a for...of loop and unshift():
Iterate through the string with a for...of loop and prepend characters using unshift().
function reverseString(str) {
const reversed = [];
for (const char of str) {
reversed.unshift(char);
}
return reversed.join("");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"21. Using the Array.from() method with a reverse loop:
Convert the string to an array, then loop in reverse and join characters.
function reverseString(str) {
const arr = Array.from(str);
let reversed = "";
for (let i = arr.length - 1; i >= 0; i--) {
reversed += arr[i];
}
return reversed;
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"22. Using Array.prototype.reduce() with substring():
Use reduce() to build the reversed string using substring().
function reverseString(str) {
return str.split("").reduce((reversed, _, index) => str.substring(index, index + 1) + reversed, "");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"23. Using the spread operator with reduce() and substring():
Use the spread operator to reverse the string using reduce() and substring().
function reverseString(str) {
return [...str].reduce((reversed, _, index) => str.substring(index, index + 1) + reversed, "");
}
const reversedString = reverseString("Hello");
console.log(reversedString); // "olleH"These are 23 different ways to reverse a string in JavaScript, each with its own implementation and approach. You can choose the one that suits your needs and coding style.
I hope this post has helped you to achieve your goals, Keep on coding.
