Question

I would like to know using jquery if a div is height constrained or not.

For example this div is constrained to 100px, whatever the size of the content the div will have 100px height:

    <div style="height: 100px;">
         bla bla
    </div> 

and this one is not constrained and will take the height of it’s content :

    <div>
          bla bla
    </div>

in other words I want to know if the height was set (and what if so) either by setting the style attribute or with a separate css style.
Thanks

Solution for FF3.6 FF5 IE8 Chrome12 and Opera11 :

function css(a){
  var sheets = document.styleSheets;
  var o={};
  var name;
  var i=0;
  while (i<sheets.length) {
    var rules = sheets[i].rules || sheets[i].cssRules;
    var r=0;
    while(r<rules.length) {
          if(typeof(rules[r].style)!="undefined" &&
             !rules[r].selectorText.match(":before") &&   // fix for FF3.6
             !rules[r].selectorText.match(":after") &&
             !rules[r].selectorText.match(":link") &&
             !rules[r].selectorText.match(":hover") &&
             !rules[r].selectorText.match(":active") &&
             !rules[r].selectorText.match(":visited") &&
             !rules[r].selectorText.match(":first-letter") &&
             !rules[r].selectorText.match(":-moz-focus-inner") &&
              a.is(rules[r].selectorText)) {
              o = $.extend(o, css2json(rules[r].style), css2json(a.attr('style')));
          }
        r++;  
      }
    i++;
  }
  return o;
}

function css2json(css){
  var s = {};
  if(!css) return s;

  var isMSIE = /*@cc_on!@*/0;

  if (isMSIE)
      {
        if(typeof(css)=="object")
          {
            for(var i in css) {
              if(i.toLowerCase) 
                s[i.toLowerCase()] = css[i];
            }
          }
        else if(typeof css == "string")
          {
            css = css.split("; ");          
            for (var i in css) {
              var l = css[i].split(": ");
              s[l[0].toLowerCase()] = (l[1]);
            };
          }
      }
    else
      {
        if(css instanceof CSSStyleDeclaration)
          {
            for(var i in css) {
              if((css[i]).toLowerCase)
                s[(css[i]).toLowerCase()] = (css[css[i]]);
            }
          }
        else if(typeof css == "string")
          {
            css = css.split("; ");          
            for (var i in css) {
              var l = css[i].split(": ");
              s[l[0].toLowerCase()] = (l[1]);
            };
          }              
      }
  return s;
}



...           
alert(css($('some selector')).height); 

Answer 1

Using the functions provided in this answer, you can access the height of the element like this:

css($('div')).height

Those functions account for both inline and inherited styles, which I believe is what you want. In the event that the height has not been explicitly specified, the height property of the returned object will be undefined.

Demo