I'll explain a little what it is conditional tags. Conditional tags are
limiting a program command on certain conditions use a specific syntax or
in plain language is a process where the process under certain conditions
should be done or not done. I guess you already know who the notion of
conditional tags, set out alone.

Conditional Tags For Targeting On Blogger Template Format

Further, like other programming languages ​​like php,
javascript, and so forth, blogger or blogspot also have conditional tags.
From what I learned conditional tags bloggers tend to be a little, easy and
simple compared to other tags conditional.

Here I am trying to register right some conditional tags in blogger or
blogspot that may be useful to you in making and editing templates.

condition #and

In layman's language if the conditions A and B conditions are met then run
this command.

In logic, yes.

<b:if cond='data:blog.pageType == "index"'> <b:if cond='data:blog.searchQuery'> <!-- Perintah ini dijalankan di halaman search_page AND index_page --> </b:if> </b:if> 

condition #OR

In layman's language if either condition A or condition B is met then run
this command.

In logic, yes.

<b:if cond='data:blog.url == data:blog.canonicalHomepageUrl + "p/foo.html"'> <!-- Perintah ini dijalankan di halaman static_site foo OR static_site bar --> <b:else/> <b:if cond='data:blog.url == data:blog.canonicalHomepageUrl + "p/bar.html"'> <!-- Perintah ini dijalankan di halaman static_site foo OR static_site bar --> </b:if> </b:if> 

condition #NOT

In layman's language if it is not in condition A, then run this command.

In logic, yes.

<b:if cond='data:blog.pageType != "index"'> <!-- Perintah ini dijalankan pada semua halaman NOT(kecuali) halaman index pages --> </b:if> <b:if cond='data:blog.url != data:blog.homepageUrl'> <!-- Perintah ini dijalankan pada semua halaman NOT(kecuali) homepage --> </b:if> 

Ok I guess up here you already know about the logic of the conditional tag
blogger or blogspot use if then else of API blogger.

Cont. Here is a list of specific conditions for a conditional tag in
blogger or blogspot

In the archive page.

<b:if cond='data:blog.pageType == "archive"'> <!-- Perintah ini dijalankan pada semua halaman archive--> </b:if> 

On the page or 404 error.

<b:if cond='data:blog.pageType == "error_page"'> <!-- Perintah ini dijalankan pada semua halaman error --> </b:if> 

In index_page.

<b:if cond='data:blog.pageType == "index"'> <!-- Perintah ini dijalankan pada semua halaman index --> </b:if> <b:if cond='data:blog.url == data:blog.homepageUrl'> <!-- Perintah ini dijalankan hanya di halaman homepage --> </b:if> 

In item

<b:if cond='data:blog.pageType == "item"'> <!-- Perintah ini dijalankan pada semua halaman item --> </b:if> <b:if cond='data:blog.url == data:blog.canonicalHomepageUrl + "2014/08/foo.html"'> <!-- Perintah ini dijalankan hanya pada halaman item dengan url namablog.com/2014/08/foo.html--> </b:if> 

On page labels

<b:if cond='data:blog.searchLabel'> <!-- Perintah ini dijalankan pada semua halaman label --> </b:if> <b:if cond='data:blog.searchLabel == "foo"'> <!-- Perintah ini dijalankan hanya pada halaman label dengan nama label 'foo' --> </b:if> 

On the search page or search

<b:if cond='data:blog.searchQuery'> <!-- Perintah ini dijalankan pada semua halaman pencarian atau search --> </b:if> <b:if cond='data:blog.searchQuery == "foo"'> <!-- Perintah ini dijalankan hanya pada halaman pencarian dengan kata kunci 'foo' --> </b:if> 

In the static page

<b:if cond='data:blog.pageType == "static_page"'> <!-- Perintah ini dijalankan pada semua halaman static atau statik --> </b:if> <b:if cond='data:blog.url == data:blog.canonicalHomepageUrl + "p/foo.html"'> <!-- Perintah ini dijalankan hanya pada halaman statik dengan nama halaman 'foo' --> </b:if> 

In the mobile custom template

<b:if cond='data:blog.isMobile == "true"'> <!-- Perintah ini dijalankan pada semua custom template mobile --> </b:if> 

Other conditions you can try search templates, respectively, such as you
find the following conditions:

<b:if cond='data:post.thumbnailUrl'> <!-- Perintah ini dijalankan jika ada perintah data:post.thumbnailUrl --> </b:if> 

This means that if

a data command: post.thumbnailUrl
not materialize or null then the tag inside the command will not be
executed.

Sample case: I do not want to show

<div class = "gmr"> Hello I is an HTML element </ div>
on a page other items that please be displayed, from here we can read the
corresponding logic.Then you have to do is insert a tag as follows:

<b:if cond='data:blog.pageType != "item"'> <div class="gmr">Halo saya adalah element HTML</div> </b:if> 

Programming should not you memorize all the existing tags, but how do you
create a logic program that can be run in accordance with our wishes or in
a cool language programming algorithms.

Easy is not it. Please play with the existing conditional tags, conditional
tags are still many who do not I have written above.

Also Read Blogger Conditional Tags

Blogger Conditional Tags