Introduction

What Are Conditional Expressions?

Conditional expressions, or simply conditionals, are a subgroup of expressions that only execute code when a certain condition is fulfilled.

Conditional expressions are a very powerful feature in any programming languages as they tell the compiler to make different decisions based on the current state of a part of the program. This allows applications to become smarter and more flexible.

Reason’s Approach

Conditionals in Reason follow a simple convention to reach an outcome:

In case <expression1> is true
Execute <expression2>
Otherwise, execute <expression3>

The logic behind conditionals allows us to form complex conditional expressions.

ReasonML has three different types of conditionals:

• if - else
• switch
• ternary operator

Each has its own flavor of convenience. At the end of this section, we’ll be familiar with the unique features of each conditional.

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In the next lesson, we’ll dive into the if-else expression.