CODEWITHSUNDEEP
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Ganesh Vellanki
Ganesh Vellanki

Reputation: 421

Checking for specific DOM element in Javascript

I have a slight problem in the code regarding the if condition check for DOM element, the requirement is that I should not allow 'BR' tag to pass

function testclick(handler) {

var nodeList = handler.childNodes;
for (var item in nodeList) {
    if (typeof (nodeList[item].tagName) !== 'undefined') {
        if (typeof (nodeList[item].tagName !== 'BR')) {
            alert(nodeList[item].tagName);
         }
      }
    }

 }

the working Jsfiddle is here http://jsfiddle.net/ganesh_vellanki/agana62d/6/

can some one suggest where I went wrong

Thanks for time

Upvotes: 2

Views: 79

Answers (3)

thefourtheye
thefourtheye

Reputation: 239693

When you do

typeof (nodeList[item].tagName) !== 'BR'

you are actually checking the type of the result of the expression

nodeList[item].tagName !== 'BR'

which will be a boolean object and it will considered truthy always. That is why your code doesn't skip BR tags. Instead, you might want to compare the tagName with BR like this

if (nodeList[item].tagName && nodeList[item].tagName.toUpperCase() !== 'BR') {
    alert(nodeList[item].tagName);
}

This converts the tagName to upper case and then compares it with BR. If they both are different, then it allows the alert to be executed.

Upvotes: 1

Domi
Domi

Reputation: 24648

You don't need typeof. This is the updated fiddle.

Code:

function testclick(handler) {
    var nodeList = handler.childNodes;
    for (var item in nodeList) {
        var tagName = nodeList[item].tagName;
        if (tagName !== 'BR' && tagName != undefined) {
            console.log(tagName);
        }
    }
}

Upvotes: 1

Derek
Derek

Reputation: 4751

Try this:

function testclick(handler) {

    var nodeList = handler.childNodes;
    for (var item in nodeList) {
        var tagName = nodeList[item].tagName !== undefined ? nodeList[item].tagName.toLowerCase() : null;
        if (tagName !== null && tagName !== 'br') {
            alert(tagName);
        }
    }

}

http://jsfiddle.net/agana62d/8/

Upvotes: 2

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