How to Convert an Array To a String in JavaScript

In JavaScript, arrays are an effective data structure that you can use to store and manage collections of values. Nevertheless, there are some circumstances in which you might need to convert an array into a string, such as when you want to display the contents of the array on a web page or send the array as a parameter in a URL.

Mainly it is done by traversing on the Array and concat value to a variable with a separator for string conversion.

Fortunately, there are several built-in methods in JavaScript that can be used to convert an array to a string.

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Contents

1. Using Loop add a separator
2. Use the toString()
3. Use the join()
4. Conclusion

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1. Using Loop add a separator

Traverse through an Array until the variable value is less than Array length and concatenate array value to a string variable.

Example

<script type='text/javascript'>
// Array
var num_arr = [23,1,65,90,34,21];

// Array length
var arr_len = num_arr.length;

var num_str = '';
 
// Traverse
for(var i=0;i< arr_len; i++){

    // Concat Array value to string variable
    num_str += num_arr[i];

    // Add separtor
    if(i < (arr_len-1) ){
         num_str += ',';
    }
}

console.log( num_str );
</script>

Output

23,1,65,90,34,21

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2. Use the toString()

This converts an Array to string and returns a comma-separated value.

Note – Its default separator is the comma(,) and it doesn’t allow to specify separator.

Syntax –

Array.toString();

Example

<script type='text/javascript'>
// Array
var names_arr = ['Yogesh','Sonarika','Vishal','Aditya'];

// Array conversion
var names_str = names_arr.toString();

console.log( names_str );
</script>

Output

Yogesh,Sonarika,Vishal,Aditya

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3. Use the join()

It also converts an Array to String and allows to specify separator. Its default separator is the comma(,).

Syntax –

Array.join();

Or

Array.join( separator );

Example

<script type='text/javascript'>
// Array
var names_arr = ['Yogesh','Sonarika','Vishal','Aditya'];

// Array conversion
var names_str = names_arr.join(' - ');
 
console.log('names : ' + names_str);
</script>

Output

Yogesh - Sonarika - Vishal - Aditya

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4. Conclusion

I showed how you can convert an Array to string with Loop and inbuilt JavaScript methods. You can use the inbuilt methods for one-line conversion.

If you want to execute some code while conversion then use Loop e.g. check Array value before concatenating.

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