Hiro Docs

Function Signature

(mod i1 i2)

Input: int, int | uint, uint | string-ascii, string-ascii | string-utf8, string-utf8 | buff, buff
Output: int | uint

Why it matters

The mod function is crucial for:

Calculating the remainder of integer division.
Implementing logic that depends on modular arithmetic.
Simplifying the process of performing operations that require remainders.
Enhancing code readability and maintainability by abstracting modular operations.

When to use it

Use mod when you need to:

Calculate the remainder of integer division.
Implement logic that depends on modular arithmetic.
Perform operations that require remainders.
Simplify and abstract modular operations.

Best Practices

Ensure the divisor is not zero to avoid runtime errors.
Use meaningful variable names for better readability.
Combine with other mathematical functions for comprehensive calculations.
Be aware of the performance implications of frequent modular operations.

Practical Example: Calculating Remainders

Let's implement a function that calculates the remainder of dividing two numbers:

(define-read-only (calculate-remainder (a int) (b int))
  (mod a b)
)

;; Usage
(calculate-remainder 5 2) ;; Returns 1
(calculate-remainder 7 3) ;; Returns 1
(calculate-remainder 10 4) ;; Returns 2

This example demonstrates:

Using mod to calculate the remainder of dividing two numbers.
Implementing a read-only function to return the remainder.
Handling both small and large input values.

Common Pitfalls

Using mod with a divisor of zero, causing a runtime error.
Assuming the result will always be positive, leading to incorrect expectations.
Not handling all possible conditions, resulting in incomplete calculations.
Overlooking the need for proper error handling and validation.

+: Adds two numbers.
-: Subtracts one number from another.
*: Multiplies two numbers.
/: Divides one number by another.

The mod function is a fundamental tool for calculating the remainder of integer division in Clarity smart contracts. It allows developers to perform modular arithmetic, enabling robust and comprehensive mathematical operations. When used effectively, mod enhances the reliability and maintainability of your smart contract code by providing a clear and concise way to manage modular calculations.

mod