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The most common way to reverse a string in JavaScript is using split(''), reverse(), join('')—it converts the string to an array, reverses it, and joins it back into a string; 2. Alternative methods include using a for loop to build the reversed string character by character, either by iterating forward and prepending characters or iterating backward; 3. A modern one-liner uses the spread syntax [...str].reverse().join(''), which is concise and functional—these methods are useful depending on performance, readability, or coding style preferences, with split('').reverse().join('') being the most widely used approach.
Reversing a string in JavaScript isn't as straightforward as calling a built-in .reverse() method on a string—since strings are immutable and don't have that method directly. But there are a few clean, common ways to do it using array methods.
Use the split(), reverse(), and join() methods
The most popular and readable approach is to:
- Split the string into an array of characters
- Reverse the array
- Join it back into a string
function reverseString(str) {
return str.split('').reverse().join('');
}
// Example
console.log(reverseString("hello")); // "olleh"This works because:
split('')turns"hello"into['h', 'e', 'l', 'l', 'o']reverse()reverses the array to['o', 'l', 'l', 'e', 'h']join('')combines it back into"olleh"
Alternative: Use a for loop (manual approach)
If you want to avoid creating extra arrays or just prefer a more manual method:
function reverseString(str) {
let reversed = '';
for (let char of str) {
reversed = char reversed;
}
return reversed;
}Or with a traditional loop:
function reverseString(str) {
let reversed = '';
for (let i = str.length - 1; i >= 0; i--) {
reversed = str[i];
}
return reversed;
}These are slightly less concise but give you more control and can be easier to understand for beginners.
One-liner with spread syntax (modern alternative)
You can also use the spread operator instead of split():
const reverseString = (str) => [...str].reverse().join('');
console.log(reverseString("world")); // "dlrow"This is clean and modern—especially useful in functional-style code.
Basically, the split('').reverse().join('') pattern is the go-to method. It's fast, readable, and widely used. The other approaches are good to know for interviews or when you want to avoid intermediate arrays.
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