i want to capture h4 heading tags which have nothing or spaces in them??

Question

i have the following text

obart on 18 September 1905. <h4>(^)</h4>Always known as Jack, he had been in the islands  arrived in Rabaul on SS <h4> </h4><i> Montoro</i> to begin a caver, and d="k987" /><a id="k988" /><a id="k989" /><a id="k990" /></p><h4 style="text-align:left;">URGENT – TERRITORY OF NEW GUINEA</h4><br /><div class="quotation">In view of the broadcast that proceed with all speed to Kieta, bringing clothing and bedding. Rations will be provided. <br /></div><div clas:black;size:1px" /><h4 style="text-align:left;"></h4></div></body></html><h4></h4>

it has fife h4 headings i want to capture those which have nothing in them or have spaces in them, can anybody help me on this? i have tried this however

(<h4.*?>)([^a-zA-Z0-9]+?)</h4>

but it doesnt see to work

Answer 1

Regular expressions are not DOM parsers. There are some built-in DOM traversal libraries, as well as external libraries, which make this sort of thing much easier.

Answer 2

Whilst I agree with eykanal that the better solution would be some for of DOM, a Regex to match tags with nothing or only spaces in them should be as simple as...

<h4.*?>\\s*?</h4>

NB. I'm not familiar with writting Regex patterns in C# but I think that should be correct.