What does === mean in R?

Table of Contents

• Introduction
• Comparison Operators in R
  • Equality with ==
    • Example
  • Strict Comparison with identical()
    • Example
• Key Differences
  • Type Coercion
  • Use Cases
• Conclusion

Introduction

In R, the === operator does not exist as a built-in operator. Instead, R provides the == operator for equality comparison and the identical() function for strict comparison. This article clarifies how these operators work in R and their differences.

Comparison Operators in R

Equality with ==

The == operator is used to check for equality between two values or objects. It performs type coercion when necessary.

Example

Strict Comparison with identical()

For strict equality checks that consider both type and value, R uses the identical() function. This function checks if two objects are exactly the same, with no coercion.

Example

Key Differences

Type Coercion

• ==: Coerces values to the same type if they are different. This can lead to unexpected results if not careful.
• identical(): Does not perform coercion. It checks both the value and type, returning TRUE only if both match exactly.

Use Cases

• Use == when you are okay with type coercion and need to compare values for equality.
• Use identical() when you need to ensure that two objects are the same in both type and value.

Conclusion

While R does not have a === operator like JavaScript, it offers the == operator for equality comparisons and the identical() function for strict comparisons. Understanding the differences between these two methods is crucial for accurate comparisons in R programming. When precise equality checking is required, prefer using identical() to avoid issues that can arise from type coercion.