Can we measure height of a div using php?

Can we measure 开发者_StackOverflow社区height of a div using php?

This is not possible at all: PHP serves HTML code. The browser renders it. Only after it is rendered, can height be determined reliably. Different browsers may end up with different heights. Different user settings (like font size) may end up with different heights.

The only way to find out an element's height is using JavaScript which runs in the browser. You can theoretically send the results back to a separate PHP script using Ajax, but I doubt that'll make much sense.

You could use jQuery's .height() like so:

var height = $("#elementID").height();

(there are native JavaScript approaches to this as well, but they tend to be a bit long and complicated.)

As others have said here, you cannot use PHP to read the height/width of a div already rendered. However, aside from the javascript options already presented keep in mind that you can use PHP to set the height/width of a div before it is sent to the browser. This would be in the form of an inline style of course. This is not the most elegant solution and to be honest I would avoid it, but you did not state what specifically it is that you want to do, and why.

Not sure if that info will help you in your implementation but it wasn't mentioned so far and thought I would contribute it.

No, we cannot. div is rendered by a browser based on CSS/JS. in a different browsers it can be different (IE, Firefox). It does not depends of PHP.

In case you are using text inside the div you could use strlen() to have some kind of measurement of height. I am saying some kind ofcourse because you are just counting the number of characters which then can be equated to some height depending on the font-size of the text, the line-height, the width of the div.

Lets say one screenheight can output 2000 characters on your website If you count 4000 characters you have 2 screenheigths. 954 characters = almost half of a screenheight ...

i have used this method once to calculate the amount of ads i could implement in the sidebanners on a blog styled website with mainly textcontent on it ...

The height of a vertical ad was about one screenheight. If the text that needed to be outputted was 7000 characters i knew i had room for 3 ads ...