Join array elements together with a delimiter in JavaScript

This post will discuss how to join elements of an array with a delimiter in JavaScript.

1. Using `Array.join()` function

One way to join elements of an array using delimiter in JavaScript is to use the Array.join() function. This function joins the elements of an array into a string, separated by a specified delimiter. For example, if we have an array of numbers and we want to convert it to a string using a dash (-) as a separator, we can do this:

let array = ["a", "b", "c", "d", "e"];

let string = array.join("-");

console.log(string); // "a-b-c-d-e"

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We can use any character or string as the delimiter, such as a comma (,), a space ( ), or a plus sign (+). If we don’t provide any argument to the join() function, it will use the default delimiter, which is a comma (,). Here’s an example:

let array = ["a", "b", "c", "d", "e"];

let string = array.join();

console.log(string); // "a,b,c,d,e"

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2. Using `Array.reduce()` function

Another way to convert an array to a string using a delimiter is to use the Array.reduce() function. This is a third built-in function that executes a reducer function on each element of the array, resulting in a single output value. We can use this function to convert an array to a string by concatenating each element with a delimiter of our choice. For example, if we have an array of strings and we want to convert it to a string using a slash (/) as the delimiter, we can do this:

let array = ["January", "February", "March"];

let q1 = array.reduce((acc, curr) => acc + "/" + curr);

console.log(q1); // "January/February/March"

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We can also provide an initial value for the accumulator as the second argument to the reduce() function. Here’s an example:

let array = ["February", "March"];

let q1 = array.reduce((acc, curr) => acc + "/" + curr, "January");

console.log(q1); // "January/February/March"

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3. Using `Array.toString()` function

This is another built-in function that returns a string representing the specified array and its elements. This function is equivalent to calling the join() function without any arguments, which means it uses a comma as the default separator. For example:

let array = ["a", "b", "c", "d", "e"];

let string = array.toString();

console.log(string); // "a,b,c,d,e"

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4. Using `Array.map()` function

We can also use other functions, such as Array.map(), to join the array elements with a delimiter and perform some additional operations on them. For example, if we want to join the array elements with a space ( ) and capitalize the first letter of each element, we can use the Array.map() function like this:

let array = ["a", "b", "c", "d", "e"];

let string = array.map(cur => cur[0].toUpperCase() + cur.slice(1)).join(", ");

console.log(string); // "A, B, C, D, E"

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That’s all about joining elements of an array with a delimiter in JavaScript.

Join array elements together with a delimiter in JavaScript

1. Using Array.join() function

2. Using Array.reduce() function

3. Using Array.toString() function

4. Using Array.map() function

Share this:

1. Using `Array.join()` function

2. Using `Array.reduce()` function

3. Using `Array.toString()` function

4. Using `Array.map()` function