Explanation and Functions of Ternary & Binary Operators in Blog - KodeRian

When customizing Blogger templates, you’ll often need to make quick decisions within your code — such as showing certain elements only if a condition is true, or providing default values when something is missing. Instead of writing long <b:if> statements, you can simplify your logic using ternary and binary operators. These two operators make your code cleaner, easier to read, and more efficient.

Introduction

In Blogger template coding, both ternary (? and :) and binary (?:) operators are used to handle conditional logic inline — meaning you can make decisions directly within a tag or expression without using multiple <b:if> blocks.

The ternary operator allows you to choose between two values based on whether a condition is true or false, while the binary operator (often called the “Elvis operator”) lets you provide a fallback value when the first one is empty or undefined.

In this article, you’ll learn the complete syntax, examples, and real-world usage for both operators, plus how to combine them for smarter and faster Blogger templates.

What Are Ternary and Binary Operators?

• Ternary Operator (? and :): Evaluates a Boolean condition and returns one of two possible values.
• Binary Operator (?:): Returns the first value if it exists; otherwise returns the second one (a fallback).

Both are incredibly useful for simplifying your Blogger expressions, especially when you’re working with template data like data:blog.title, data:view.isHomepage, or data:post.labels.

Syntax Overview

Ternary Operator Syntax

{boolean} ? {value if true} : {value if false}

Binary Operator Syntax

{value1} ?: {value2}

Now let’s explore both in more depth and see how they behave in Blogger.

Ternary Operator Explained

The ternary operator works with three operands:

1. A Boolean condition that determines which value to return.
2. The value returned if the condition is true.
3. The value returned if the condition is false.

This operator is especially handy when toggling between two states (like public/private or on/off), choosing between two strings, or limiting data based on a condition.

Syntax Example

{boolean} ? {value if true} : {value if false}

For example:

<b:eval expr='data:blog.isPrivate ? "Private" : "Public"' />

If the blog is set to private, it will display “Private.” Otherwise, it shows “Public.”

Supported Value Types

• Boolean values: True or false conditions, such as data:view.isHomepage.
• Strings: Text data like "Public" or "Private".
• Numbers: You can use it to switch between numeric states (e.g., 0 or 1).
• Arrays: Use it to decide which list of posts or elements to render.

Example 1 — Ternary with String

<b:with var='status' value='data:blog.isPrivate ? "Private" : "Public"'>
  <b:eval expr='"This blog is " + data:status'/>
</b:with>

If the condition is true, the result is “This blog is Private”; otherwise, “This blog is Public.”

Example 2 — Ternary with Number

<b:with var='flag' value='data:blog.isPrivate ? "0" : "1"'>
  <b:eval expr='data:flag'/>
</b:with>

This returns 0 if the blog is private and 1 if it’s public. Useful for binary flags or conditions in scripts.

Example 3 — Ternary with Array

<b:loop var='post' values='data:view.isHomepage ? data:posts limit 5 : data:posts'>
  <b:include name='postSnippet' data='post'/>
</b:loop>

This will limit posts to 5 items on the homepage but show all posts elsewhere.

Binary Operator Explained

The binary operator (or Elvis operator) provides a quick fallback when the first value is empty or undefined. It only works with two operands:

value1 ?: value2

If value1 contains data, it’s used. Otherwise, value2 is returned instead. This helps you create fallback text, links, or metadata in your Blogger theme.

Example — String Fallback

<b:eval expr='data:blog.pageName ?: data:blog.title'/>

This displays the page name if available; otherwise, it shows the blog title. It’s one of the simplest and most practical uses of the binary operator.

More Examples

• Thumbnail Fallback:
  

  <img expr:src='data:post.firstImageUrl ?: "https://example.com/placeholder.png"' />

  If a post doesn’t have a featured image, it displays a default placeholder.
• Title Fallback:
  

  <b:eval expr='data:post.title ?: "Untitled Post"' />

  If a post has no title, this will show “Untitled Post.”
• Author Name Fallback:
  

  <b:eval expr='data:post.author.displayName ?: "Guest Writer"' />

  Displays “Guest Writer” if author data is missing.

When to Use Ternary vs Binary Operators

Operator	Use Case	Example
Ternary ( ? : )	When you want to choose between two values based on a condition.	data:view.isHomepage ? "Home" : "Page"
Binary ( ?: )	When you want a fallback if the first value is empty or undefined.	data:post.title ?: data:blog.title

Step-by-Step: How to Use in Blogger Template

1. Go to Blogger Dashboard → Theme → Edit HTML.
2. Locate a section where you’d use a conditional, like <b:if> or <b:eval>.
3. Replace long conditions with a shorter ternary or binary expression.
4. Use " for quotes inside Blogger expressions to prevent errors.
5. Preview and save your template after confirming output correctness.

Advanced Tips

• Combine Operators: You can nest ternary and binary logic for advanced conditions.
• Keep it Readable: Avoid stacking more than two ternaries in one line — readability matters.
• Test Both States: Always check true and false outcomes to ensure correct rendering.
• Use with Expressions: Ternary works great inside expr:text, expr:class, and expr:href attributes.

Example — Combined Logic

<b:eval expr='data:view.isHomepage ? data:blog.title : (data:blog.pageName ?: "My Blog")'/>

This displays the blog title on the homepage, otherwise the page name — or a default title if neither exists.

Troubleshooting

• Template Error: If Blogger says “Error parsing XML,” check your quotation marks and replace double quotes with ".
• Blank Output: Ensure the variables you’re referencing (like data:post.title) actually exist on that page.
• Nested Logic Not Working: Wrap complex expressions inside <b:with> to make them easier to handle.

FAQ

Can I use these operators inside attributes?

Yes. They work in expr:href, expr:src, expr:class, and expr:text. It’s great for dynamic styling or content changes.

What’s the difference between ?: and ? :?

? : uses a condition to decide between two values (true or false). ?: simply checks if the first value exists — no Boolean logic required.

Can I use them together?

Yes. You can combine them for cleaner multi-level logic, like this:

<b:eval expr='data:view.isItem ? data:post.title : (data:blog.pageName ?: data:blog.title)' />

Do these affect performance?

No. They actually improve readability and load performance slightly, since Blogger renders simpler logic faster.

Conclusion

The ternary and binary operators are simple yet powerful tools that make your Blogger templates cleaner and smarter. Whether you’re toggling text, setting defaults, or changing layouts dynamically, these operators help you write compact logic without cluttering your code.

Once you understand how to use ? : and ?:, you’ll find dozens of ways to simplify your theme — from custom meta titles to conditional widgets, thumbnail fallbacks, and even dynamic footers. Practice on a copy of your template and see how much cleaner your HTML becomes!

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