Question

I am trying to write a Javascript that sorts some paragraphs. Here’s a small snippit of the HTML that I am sorting:

<p>Brown, John, 2010, <a href="#">Link</a></p>

<p>Bush, C.A., 2010, <a href="#">Link</a>: More info.</p>

<p><br></p>
<h3><a name="c">C</a></h3>

<p>Caine, J.S., and Minor, S.A., 2010, <a href="#">Link</a>: More</p>

This Javascript is looking for the entries that contain “2010” (which are 3 out of the 4 paragraphs):

var paras = document.getElementsByTagName("p");
alert( paras.length );  // 4, which is what I expect!

for( i=0; i < paras.length ; i++ ) {
    var node0_text = paras[i].childNodes[0].nodeValue;

    if ( node0_text.indexOf('2010') ) {
        alert( node0_text ); // not returning everything that I expect it to.
    };
}

When I run this the first 2 entries (“Brown” and “Bush”) pop up in the alert box just as I expect they would. Then the script seems to die. It does not display the third (“Caine”) entry. What went wrong here? Thanks for any input.

A link to it: http://jsfiddle.net/Jrmy/6MP2W/5/

Answer 1

The “Caine” entry is in the fourth paragraph. The script fails because the third paragraph has no text.

This is the third paragraph:

<p><br></p>

The text is null so the if statement gets an exception for trying to access .indexOf().

(edit — a good comment points out that it’s the <br> tag being checked for a value, but that’s null too.)