Why are array strings separated by a comma?

Question

I'm trying to make a list from info the user enters.

   var todoArray = new Array();

document.getElementById("addButton").onclick = function(){

    var temp = document.getElementById("inputBox").value;
    var appendTemp = "<li><input type=\"checkbox\">" + temp + "</li>";

    todoArray.push(appendTemp);

    document.getElementById("todoListUL").innerHTML = todoArray;

    console.log(todoArray);

}

But when the list times show up, they all have a comma between them, JSFiddle link for imagery here: JSFiddle

Why are they separated by this comma and how do I remove it?

Because that's how an array's toString() is implicitly called when you try to make an array a string - in document.getElementById("todoListUL").innerHTML = todoArray; — baao
– baao, Commented May 7, 2018 at 12:44

Pointy · Accepted Answer · 2018-05-07 12:44:27Z

4

When you assign any value to the .innerHTML property of an element, the value is implicitly converted to a string and then parsed as HTML. The default way that an array is converted to a string is via the .join() method, and the default array separator is a comma.

If you don't want anything, you can just call .join() yourself:

document.getElementById("todoListUL").innerHTML = todoArray.join("");

answered May 7, 2018 at 12:44

Pointy

415k62 gold badges600 silver badges631 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Mihai Alexandru-Ionut · Accepted Answer · 2018-05-07 13:25:50Z

1

The issue is in this line:

document.getElementById("todoListUL").innerHTML = todoArray;

because the right member is converted to string and it is invoked internally the join method for todoArray array and default delimiter is comma.

Change it to

document.getElementById("todoListUL").innerHTML = todoArray.join("");

edited May 7, 2018 at 13:25

answered May 7, 2018 at 12:44

Mihai Alexandru-Ionut

48.6k14 gold badges106 silver badges132 bronze badges

1 Comment

J. Doe Over a year ago

Thank you! This fixed it and helped me understand the issue. Cheers!

Collectives™ on Stack Overflow

Why are array strings separated by a comma?

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related