190

I have an array:

a.value = [a,b,c,d,e,f]

How can I convert to comma-seperated string like:

a.value = "a,b,c,d,e,f"

3
  • 12
    a.value = a.value.join() Commented Sep 29, 2016 at 13:04
  • 7
    Array.toString() returns comma seperated string by default Commented Sep 29, 2016 at 13:08
  • 2
    You can use let comma_seprated = a.value.join() or let comma_seprated = a.value.join(", ") Commented May 26, 2021 at 6:11

3 Answers 3

330

The method array.toString() actually calls array.join() which result in a string concatenated by commas. ref

var array = ['a','b','c','d','e','f'];
document.write(array.toString()); // "a,b,c,d,e,f"

Also, you can implicitly call Array.toString() by making javascript coerce the Array to an string, like:

//will implicitly call array.toString()
str = ""+array;
str = `${array}`;

Array.prototype.join()

The join() method joins all elements of an array into a string.

Arguments:

It accepts a separator as argument, but the default is already a comma ,

str = arr.join([separator = ','])

Examples:

var array = ['A', 'B', 'C'];
var myVar1 = array.join();      // 'A,B,C'
var myVar2 = array.join(', ');  // 'A, B, C'
var myVar3 = array.join(' + '); // 'A + B + C'
var myVar4 = array.join('');    // 'ABC'

Note:

If any element of the array is undefined or null , it is treated as an empty string.

Browser support:

It is available pretty much everywhere today, since IE 5.5 (1999~2000).

References

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Comments

47

Use the join method from the Array type.

a.value = [a, b, c, d, e, f];
var stringValueYouWant = a.join();

The join method will return a string that is the concatenation of all the array elements. It will use the first parameter you pass as a separator - if you don't use one, it will use the default separator, which is the comma.

Comments

15

You can simply use JavaScripts join() function for that. This would simply look like a.value.join(','). The output would be a string though.

Comments

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