Tag: tricks
Nabin Nepal (Starx) .net c operators tricks
November 4, 2012

?: Operator return void

Question by Artur Keyan

Artur KeyanArtur Keyan

I want to use the ?: operator intstead of if else

e.g.

var directory = new DirectoryInfo(path);
if (!directory.Exist())
{
    directory.Create();
}
else 
{
    // do nothing
}

I tried to use ?: like this: 

var directory = new DirectoryInfo(path);
!directory.Exist() ? directory.Create() : void;

but it says “Invalid expression term ‘void’“, null also isn’t working.

Can anyone tell me a solution? Thanks.

Answer by Starx

StarxStarx

Ternary operator are not designed to replace if/else They are to simplify assignment and declaration. It should be able to assign the result the statement to something like variable or function. There major use are in assignment or reading.

Something like

var status = !directory.Exist() ? directory.Create() : false;

The correct solution would be to stick to native if condition. The following is enough:

var directory = new DirectoryInfo(path);
if (!directory.Exist())
{
    directory.Create();
}
Nabin Nepal (Starx) css height html tricks

100% height of content – px

Question by Vladimir

VladimirVladimir

I have a page with height 100%:

<div id="wrapper">
    <header id="header" class="clearfix">

    </header>
    <div class="main-container clearfix">
        <aside id="sideLeft">

        </aside><!-- #sideLeft -->
        <div id="content">
            <div id="map_canvas"></div>
        </div>
    </div> <!-- #main-container -->
</div><!-- #wrapper -->

CSS:

* {
    margin: 0;
    padding: 0;
}
html, body {
    height: 100%;
    min-height: 100%;
}
#wrapper {
    width: 100%;
    height: 100%;
}
#header {
    width: 100%;
height: 45px;
}
.main-container {
    width: 100%;
    height: 100%;
    min-height: 100%;
}

#content {
    height: 100%;
margin-left: 20%;
}

#map_canvas {
    height: 100%;
    width: 100%;
}
#sideLeft {
    height: 100%;
    width: 20%;
    float: left;
}

But I want to make content 100% – height of header (in px), to don’t show scrolling on the page.

I try to add position: absolute; to #header and .main-container but it’s not helping (scroll still showing).

Live example: http://indoor.powerhtml.ru/30/index.html

Answer by Starx

StarxStarx

CSS cannot perform calculations and manipulation on page, it is just a stylesheet. You have to use JS for this.

jQuery snippet to do what you want is

$("#header").height($("#header").height()); //This automatically converts % to px

Check it out

...

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