Hiro Docs

Function Signature

(string-to-int? string)

Input: (string-ascii 1048576) | (string-utf8 262144)
Output: (optional int)

Why it matters

The string-to-int? function is crucial for:

Converting string representations of numbers to integers.
Implementing logic that requires numeric values from string inputs.
Ensuring data integrity by validating string-to-integer conversions.
Simplifying the process of handling numeric conversions in smart contracts.

When to use it

Use string-to-int? when you need to:

Convert a string representation of a number to an integer.
Implement logic that requires numeric values from string inputs.
Validate string-to-integer conversions to ensure data integrity.
Handle numeric conversions in your smart contract.

Best Practices

Ensure the input string is correctly formatted and represents a valid integer.
Use meaningful variable names for better readability.
Combine with other string and numeric functions for comprehensive data management.
Handle the possible error cases to ensure robust contract behavior.

Practical Example: Converting a String to an Integer

Let's implement a function that converts a string to an optional integer:

(define-read-only (convert-string-to-int (input (string-ascii 20)))
  (string-to-int? input)
)

;; Usage
(convert-string-to-int "123") ;; Returns (some 123)
(convert-string-to-int "-456") ;; Returns (some -456)
(convert-string-to-int "abc") ;; Returns none

This example demonstrates:

Using string-to-int? to convert a string to an optional integer.
Implementing a public function to handle the string-to-integer conversion.
Handling both valid and invalid string inputs.

Common Pitfalls

Using string-to-int? with incorrectly formatted or invalid string inputs, causing the operation to return none.
Assuming the conversion will always succeed, leading to unhandled error cases.
Not handling all possible conditions, resulting in incomplete data management.
Overlooking the need for proper error handling and validation.

string-to-uint?: Converts a string to an optional unsigned integer.
int-to-ascii: Converts an integer to a string-ascii representation.
int-to-utf8: Converts an integer to a string-utf8 representation.

The string-to-int? function is a fundamental tool for converting string representations of numbers to integers in Clarity smart contracts. It allows developers to implement logic that requires numeric values from string inputs, ensuring data integrity and simplifying numeric conversions. When used effectively, string-to-int? enhances the reliability and maintainability of your smart contract code by providing a clear and concise way to handle string-to-integer conversions.

string-to-int?