Understanding and Using the Operator Contains in Blogger Template Code - KodeRian

Operator contains is one of the most useful logical operators available in Blogger’s template language, yet many creators rarely use it to its full potential. This operator allows you to check whether a certain string or piece of text exists within another string. In simple terms, it helps you perform text matching operations directly inside Blogger’s XML conditions—something incredibly handy when customizing layouts, widgets, or displaying specific elements only when certain keywords exist in your data.

In this article, we’ll explore the function, syntax, and real-world applications of the contains operator in Blogger. By the end, you’ll know how to use it for smart conditions, dynamic content, and even layered logic inside your Blogger templates. Let’s dive in.

What Is the contains Operator?

In Blogger’s XML template syntax, the contains operator is used to check if one string is found inside another. It returns a Boolean value—either true or false—depending on whether the condition is met.

For instance, if we have a string named "Koderian" and we check whether it contains the substring "Kode", the condition will return true because the substring “Kode” is part of “Koderian.”

This operator is especially powerful when used to check data values such as blog titles, labels, or even page types in Blogger’s dynamic data tags (like data:blog.title or data:post.labels).

Why It Matters for Blogger Customization

The contains operator gives you more control over your theme’s behavior without needing external JavaScript. For example, you can:

• Show or hide certain widgets depending on a keyword in the post title or label.
• Create conditional designs for specific pages (e.g., show a special banner when the URL contains “promo”).
• Filter or highlight posts dynamically in a section.
• Reduce template complexity by avoiding repetitive <b:if> conditions.

In short, it allows you to create smarter, more flexible templates that react to your blog’s data in real time.

Basic Syntax

The general form of the contains operator is as follows:

{string} contains {string}

Key Rules:

• The result will always be a Boolean value (true or false).
• Both operands must be strings, either literal text or Blogger data expressions.
• You can use explicit values, Blogger data variables, or even nested expressions.
• It can be combined with other logical operators such as and, or, or not.
• It can also compare values inside arrays, such as lists of labels or categories.

Let’s explore a few practical examples to make it clearer.

Examples of Using contains in Blogger

1. Comparing Two Explicit String Values

<b:if cond="&quot;Koderian&quot; contains &quot;Kode&quot;">
  <div>Result: True</div>
</b:if>

Explanation: The string “Koderian” contains “Kode”, so the condition evaluates to true. This means the content inside <b:if> will be displayed.

2. Comparing Data Value with an Explicit String

<b:if cond='data:blog.title contains &quot;rian&quot;'>
  <div>Your blog title contains "rian"!</div>
</b:if>

If your blog title is “Koderian”, the condition will again return true because “rian” appears in “Koderian”.

3. Comparing Two Data Values

<b:if cond='data:blog.pageTitle contains data:blog.title'>
  <div>Page title includes blog title.</div>
</b:if>

This is useful for checking if a page’s title already includes the main blog name, which can help you avoid duplicating text in SEO titles or headings.

Alternative Functional Syntax

Besides the standard syntax, Blogger also supports a function-style version:

contains({string},{string})

This version can be handy when dealing with multiple nested operations or when using advanced logic chains. However, since Blogger supports only a limited number of operators, this approach is less common.

Example Using Functional Syntax

<b:if cond='contains(data:blog.title, &quot;Kode&quot;)'>
  <div>Your blog title includes the word "Kode".</div>
</b:if>

The result remains the same: true if the string “Kode” is part of your blog’s title.

Practical Use Cases in Blogger Templates

Let’s go through some practical ways you can use the contains operator in your Blogger themes:

1. Show a Banner Only on Posts with Specific Labels

<b:if cond='data:post.labels contains &quot;Featured&quot;'>
  <div class="featured-banner">This is a featured post!</div>
</b:if>

This will show a special banner whenever a post has the “Featured” label.

2. Add Custom CSS for Certain Pages

<b:if cond='data:blog.pageName contains &quot;About&quot;'>
  <style>
    body { background: #f5f5f5; }
  </style>
</b:if>

This method lets you style your “About” page differently from the rest of your site—without using JavaScript or external classes.

3. Display Widgets Conditionally

<b:if cond='data:blog.url contains &quot;/search/label/News&quot;'>
  <div class="news-widget">Latest News Section</div>
</b:if>

Using this technique, you can display certain widgets only on category pages that match a specific label.

Advanced Tips for Using contains

• Case Sensitivity: Blogger’s contains comparison is case-sensitive. “Code” and “code” are treated as different strings.
• Combine With Logical Operators: You can chain multiple conditions using and / or.
• Nested Logic: It’s possible to use contains inside another condition, but keep your structure clean for readability.
• Debugging Tip: If your condition isn’t working, print the value using <data:variableName/> to verify the string.

Example with Multiple Conditions

<b:if cond='data:blog.pageTitle contains &quot;Blogger&quot; or data:blog.pageTitle contains &quot;Tutorial&quot;'>
  <div>This page is about Blogger or Tutorial!</div>
</b:if>

Common Mistakes and Troubleshooting

• Forgetting Quotation Marks: Always enclose string values with " in Blogger XML.
• Using Wrong Data Reference: Double-check whether you’re using data:blog.title, data:post.title, or data:blog.pageTitle.
• Encoding Issues: When copying code, Blogger may escape certain symbols. Use proper " instead of ".
• Logic Overlap: Make sure your nested <b:if> tags are properly closed to prevent template parsing errors.

FAQ About Blogger’s contains Operator

1. Is the contains operator case-sensitive?

Yes, it is. For example, “Blogger” and “blogger” are different strings. If you want to make your checks case-insensitive, you’d need to normalize your text using JavaScript or consistent capitalization in your data.

2. Can I use contains to check labels?

Absolutely. It’s perfect for checking if a post’s label list includes a specific term, such as “Anime,” “Tutorial,” or “Review.”

3. Does it work in all Blogger themes?

Yes, as long as your theme uses the new Blogger template system (which nearly all modern ones do). Older classic templates might not support it fully.

4. Can I use it with arrays?

Yes. When working with label lists or similar arrays, Blogger evaluates whether the target string is part of the array values.

Conclusion

The contains operator is a small but powerful tool inside the Blogger template language. With it, you can create dynamic conditions, personalize layouts, and simplify template logic—without touching JavaScript. Whether you’re checking titles, labels, or URLs, mastering contains makes your Blogger site far more flexible and intelligent.

Keep experimenting with different data expressions and nested conditions to find what works best for your theme. Once you get used to this operator, you’ll realize how many possibilities it opens for conditional design and smart automation inside Blogger.

Final Thoughts

That wraps up this tutorial on the Blogger contains operator. Hopefully, this guide helped you understand not only how it works, but also how to apply it effectively in real situations. Don’t forget to bookmark this page or share it with other Blogger developers who might find it useful. Stay tuned for more Blogger coding tips and tricks from KodeRian.