javascript

Join array items and convert to string in javascript

September 18, 2022

We can use Array.join() method to join all the elements of the array and convert them to a string. By default, it will join the items with a comma seperator.

const names = ["Rick", "Grimes", "Carol", "Alicia"];

//Join with default sepearor ,
name_str_1 = names.join();
console.log(name_str_1);
// -> Rick,Grimes,Carol,Alicia

//Jon with space seperator
name_str_2 = names.join(" ");
console.log(name_str_2);
// -> Rick Grimes Carol Alicia

You can pass separator inside join() method if you want to join the array items other than comma operator.

In the code snippet, we have an array named names that contain multiple items. We are joining those items using names.join() method.

Live Demo

Array.join() function

In Javascript, the Array.join() function is used to join the elements of an array into a string. The string is created by concatenating the elements of the array, separated by a specified separator string. If no separator is specified, a comma is used by default.

Syntax

Array.join(separator)

Steps to create a string from array items using join() function

Create an array that contains one or multiple items.
Use arr.join(separator) to create the new string. The function will also return the string.

Code example

const arr = ["H", "el", "l", "o"];

console.log(arr.join(''));

// -> Hello

Try it yourself

Concatenate Array items to a String using For Loop

We can also use For loop to join the array items and generate a String from them if we do not want to use any function like Array.join(). To join the String from Array items:

Create an array that contains multiple string items.
Create a string type variable that will contain the result string.
Loop through the array and in each iteration append the array item to the variable defined above.
After the loop id is finished we will get the final string in the string type variable.

const arr = ["H", "el", "l", "o"];

var result_str = '';

for (var i = 0; i < arr.length; i++) {
    result_str += arr[i];
}

console.log(result_str);

Output

Hello

Live Demo

In the above code example, we have defined an array - arr. We have also created a string variable called result_str that contains an empty string.

Then, we initiated a For loop on the array - arr and in each iteration, we are adding array item to the result_str variable.

After that, we are printing the final result from the result_str variable to the console window.

Join items using Array.forEach() function

We cal also use Array.forEach() function to join the array items and create a list from them.

var arr = ["D", "e", "v", "s", "h", "e", "e", "t"];

result = ""

arr.forEach( item => result += item )

console.log(result);

Output

Devsheet

Live Demo of joining array items using Array.forEach

The above code example will loop through the array and add each item to the result string. The result will be logged to the console as a single string.

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