Partition a string into chunks of given size in JavaScript

This post will discuss how to partition a string into chunks of given size in JavaScript.

To partition a string into chunks of given size in JavaScript, there are several approaches we can take. Here are three possible solutions:

1. Using a loop and slicing

This is a simple and straightforward way to iterate over the string using a for loop and use the slice() or substring() function to extract a substring of the desired length at each iteration. The slice() function returns a part of the string from a start index to an end index. We can use a for loop to increment the start and end indexes by the chunk size, and push the substrings to an array. For example, if we want to partition a string into chunks of 3 characters, we can use this function:

function partition(str, chunkSize) {

let chunks = [];

for (let i = 0; i < str.length; i += chunkSize) {

chunks.push(str.slice(i, i + chunkSize));

}

return chunks;

}

let str = "Hello world!";

let result = partition(str, 3);

console.log(result); // ["Hel", "lo ", "wor", "ld!"]

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2. Using `String.match()` function

This is a more concise and elegant way to partition a string into chunks of the given size using a regular expression that matches any character (.) exactly n times ({n}), where n is the chunk size. We can use the match() function to get an array of the matched substrings. For example, if we want to partition a string into chunks of 3 characters, we can use str.match(/.{1,3}/g). This will return an array of substrings, or null if the string is empty.

function partition(str, chunkSize) {

let regex = new RegExp(`.{1,{chunkSize}}`, 'g');

return str.match(regex);

}

let str = "Hello world!";

let result = partition(str, 3);

console.log(result); // ["Hel", "lo ", "wor", "ld!"]

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3. Using recursion and slicing

We can also use a recursive function to partition a string into chunks of a fixed size. Recursion can be used to divide a problem into smaller subproblems that are easier to solve. The idea is to use the slice() function to get the first chunk of the string, and then call the function again with the remaining part of the string. The base case is when the string is empty or shorter than the chunk size. For example, if we want to partition the string "Hello world!" into chunks of size 3, we can write:

function partition(str, chunkSize) {

// Base case: if the string is empty or shorter than the chunk size, return it as an array

if (str.length <= chunkSize) {

return [str];

}

// Recursive case: get the first chunk and concatenate it with the recursive call on the rest of the string

return [str.slice(0, chunkSize)].concat(partition(str.slice(chunkSize), chunkSize));

}

let str = "Hello world!";

let result = partition(str, 3);

console.log(result); // ["Hel", "lo ", "wor", "ld!"]

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That’s all about partitioning a string into chunks of given size in JavaScript.

Partition a string into chunks of given size in JavaScript

1. Using a loop and slicing

2. Using String.match() function

3. Using recursion and slicing

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2. Using `String.match()` function