---
title: "Using Conditional Blocks in C#"
---


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## Purpose Summary

This page explains how to use conditional blocks in templates to control dynamic document output.

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You can use different document blocks to represent the same data depending on a condition with the help of conditional blocks. A *conditional block* represents a set of template options, each of which is bound with a conditional expression. At runtime, these conditional expressions are sequentially evaluated, until an expression that returns `true` is reached. Then, the conditional block is replaced with the corresponding template option populated with data.

A conditional block can have a default template option that is not bound with a conditional expression. At runtime, this template option is used, when none of the conditional expressions return `true`. If a default template option is missing and none of the conditional expressions return `true`, then the whole conditional block is removed during runtime.

You can use the following syntax to declare a conditional block.

{{< highlight csharp >}}
<<if [conditional_expression1]>>
template_option1
<<elseif [conditional_expression2]>>
template_option2
...
<<else>>
default_template_option
<</if>>
{{< /highlight >}}

**Note** – A conditional expression must return a `Boolean` value.

**This section includes the following topics:** 

- [Working with Common Conditional Blocks](/words/net/working-with-common-conditional-blocks/)
- [Working with Table-Row Conditional Blocks](/words/net/working-with-table-row-conditional-blocks/)
- [Working with Table-Column Conditional Blocks](/words/net/working-with-table-column-conditional-blocks/)