Javascript Arrays printing undefined before the array items

Question

I am having trouble printing a simple array list in javascript. undefined is being printed before only two array items. please consider the code below;

function buildList(){
    var box = document.getElementById("box");
	var startList  = "<ol>";
	var endList = "</ol>";
	var listItems;
      
        var arry = ["Go to shopping", "Go to Mall"];
  	for(var i = 0; i < arry.length; i++){
            listItems += "<li>" + arry[i] + "</li>";
	}

	box.innerHTML = startList + listItems + endList;
}
document.onLoad(buildList());``

<div id="box">
  
</div>

output of this is

undefined 1) Go to shopping 2) Go to Mall

Please help.

Hi @knight, if any answer has solved your question please consider accepting it by clicking the check-mark. This indicates to the wider community that you've found a solution and gives some reputation to both the answerer and yourself. There is no obligation to do this. — Sarath Chandra
– Sarath Chandra, Commented May 6, 2016 at 11:32

Sarath Chandra · Accepted Answer · 2015-08-14 20:42:16Z

6

Your listItem variable is undefined because it is not initialized.

var listItems = "" ; (at line 5) should solve your problem.

edited Aug 14, 2015 at 20:42

answered Aug 14, 2015 at 20:29

Sarath Chandra

1,87621 silver badges40 bronze badges

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

Comments

taxicala · Accepted Answer · 2015-08-14 20:30:28Z

3

You are declaring var listItems; => undefined, you should do as follows: var listItems = ""; => declared and initialized as an empty string.

answered Aug 14, 2015 at 20:30

taxicala

21.8k7 gold badges41 silver badges67 bronze badges

Comments

kot09 · Accepted Answer · 2015-08-14 20:30:38Z

2

You have to initialize listItems.

var listItems = "";

What you are doing right now is adding a string to listItems, but you did not define listItems. It does not know what is listItem

answered Aug 14, 2015 at 20:30

kot09

1,0473 gold badges11 silver badges18 bronze badges

Comments

shas · Accepted Answer · 2015-08-14 20:37:31Z

0

Try this. In your code you missing var listItems="";

Here is full code

function buildList()
       {
	   var box = document.getElementById("box");
	   var startList  = "<ol>";
	   var endList = "</ol>";
	   var listItems="";

	   var arry = ["Go to shopping", "Go to Mall"];

	    for(var i = 0; i < arry.length; i++)
	    {
		listItems += "<li>" + arry[i] + "</li>";
	   }

	  box.innerHTML = startList + listItems + endList;
      }

       document.onLoad(buildList());``

<div id="box">
  
  </div>

answered Aug 14, 2015 at 20:37

shas

7032 gold badges9 silver badges32 bronze badges

Collectives™ on Stack Overflow

Javascript Arrays printing undefined before the array items

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related