Question

how to split <p><span>Hello</span></p> to <span>Hello</span> using javascript

var text = "<p><span>Hello</span></p>";

remember:I don’t know what contain <p>, I don’t know if <p> has any attribute or not

I found the answer !

var patt=/^<p.*?>(.*)<\/p>$/i;
var result=patt.exec(text);
alert(result[1]); 

thank’s ring0 & w3schools
http://www.w3schools.com/jsref/jsref_obj_regexp.asp

but there is problem ! it doesn’t work with

aa<p><span>Hello</span></p>aa

Answer 1

A regular expression that takes care of removing p attributes

var new = text.replace(/^<p[^>]*>(.*)<\/p>$/i, "$1");

Or a version with .*?

var new = text.replace(/^<p.*?>(.*)<\/p>$/i, "$1");

And if <pre> or <param> may start the text, you have to prevent a match

var new = text.replace(/^<p\b.*?>(.*)<\/p>$/i, "$1");

edit to answer your second question

To remove whatever is before / after

var new = text.replace(/^.*<p\b[^>]*>(.*)<\/p>.*$/i, "$1");

But if you want to remove all <p...> and all </p>, you should use the two lines

var new = text.replace(/<p\b.*?>/ig, "");
new = text.replace(/<\/p>/ig, "");