Question

I am unable to understand the behavior of for loop.
jquery:

 $('#btnTest').on("click", function () {

            var thumbUrl = "http:localhost/File/Modules/FileManager/Library/1041323042_12.jpg";
            var arrurl = thumbUrl.split("/");
            var i;
            var result;
            for (i = 0; i < arrurl.length - 1; i++) {
                result += arrurl[i] + '/';
            }
            alert(result);
 });

and html:

<input type="button" class="ThumbLink" value="Test" id="btnTest"/>

But alert gives a result:

undefinedhttp:localhost/File/Modules/FileManager/Library/

Where this undefined comes from.What is my mistake in for loop ?.Thanks.

My jsfiddle:

jsfiddle

Answer 1

Maybe, since you’re simply appending to result each time through the loop, you may want to set it initially to something other than undefined.

:
var result = "";
for (i = 0; i < arrurl.length - 1; i++) {
    result += arrurl[i] + '/';
}
alert(result);
:

Making that change to your jsfiddle link results in the correct output:

http:localhost/File/Modules/FileManager/Library/