CODEWITHSUNDEEP
javascriptjqueryhtmlundefined
fazil
fazil

Reputation: 21

When i write the script it shows TypeError: menuLi[i] is undefined

This is my code 

var menuLi=[];
$(window).load(function() {
var menuUl = document.getElementById("sub");                                          
menuLi = menuUl.getElementsByTagName("LI");
var len = menuUl.childNodes.length;

    nSpan = document.createElement("SPAN");
    var findUl;

    for (var i = 0; i < len; i++) {
        findUl = menuLi[i].getElementsByTagName("UL");
        liLen = findUl.length;
        if (liLen > 0) {
            menuLi[i].classList.add("myNew");
        }
    }
});

The above is my code which throws error menuLi[i] is undefined.

Upvotes: 1

Views: 54

Answers (2)

cнŝdk
cнŝdk

Reputation: 32145

Problem:

In fact you are looping using the wrong length.

Explanation:

Because the menuLi.length is lower than menuUl.childNodes.length, as menuUl.childNodes will contain all the li inside menuUl and their children.

So menuUl.childNodes.length is the number of li elements multiplied by the number of elements in each li.

So i will get greater than the menuLi.length, and that explains why you got menuLi[i] is undefined, because if you have only 5 li in menuUl and for example you are trying to get menuLi[8], where menuLi[8] is undefined.

Solution:

So just use:

var len = menuLi.length;

Upvotes: 1

Alex McMillan
Alex McMillan

Reputation: 17952

You are looping from 1 to menuUl.childNodes.length using i, but you are indexing straight into menuUl[i]. Do you mean menuUl.childNodes[i]?

Upvotes: 0

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