Скачать или смотреть How to Convert String Values to Float in Swift Arrays

Learn how to effectively change string values to float in your Swift arrays, particularly when handling data retrieved from APIs!
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This video is based on the question https://stackoverflow.com/q/73049953/ asked by the user 'Abhi' ( https://stackoverflow.com/u/19300598/ ) and on the answer https://stackoverflow.com/a/73050537/ provided by the user 'SwiftCoderVaibhav' ( https://stackoverflow.com/u/4225829/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Transforming String Values to Float in Swift Arrays

When working with data retrieved from APIs in Swift, it's not uncommon to encounter values stored as strings that require conversion to other data types for further processing. One common scenario is when you have an array of dictionaries (or JSON data) containing numeric values in string format, and you want to convert them into float values for calculations or data handling. In this guide, we will address how to convert string values to float in a simple and structured approach.

Understanding the Problem

You may be fetching data, such as student grades, weights, and credits, from an API like the one displayed in the question. The values you are often interested in (like grades, weights, and credits) come as strings. To perform calculations or comparisons with these values, you'll need to convert them to Float.

For example, a grade like "85.50" needs to be turned into 85.50 as a float in your Swift program.

Breaking Down the Solution

To achieve the transformation of string values to float, we will customize a model class using Swift's Codable protocol. This process includes defining your data model and implementing a custom initializer to handle the conversion.

Step 1: Define the Data Model

First, create a model class that conforms to the Codable protocol. This class will represent the structure of the data you are retrieving.

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Implement the Changes in Your Completion Block

In your completion block, which handles the response data from the API, you will utilize this model:

[[See Video to Reveal this Text or Code Snippet]]

Key Points to Note

CodingKeys: This enum allows you to map the JSON keys to your properties elegantly. By defining the keys, Swift will know how to match the keys from the JSON with your model properties.

Optional Handling: I used Float(gradeString) ?? 0.0 to ensure that if the conversion fails (e.g., the string is not a valid number), it defaults to 0.0. This helps in preventing crashes due to unexpected data formats.

Conclusion

By following the steps above, you can effectively change string representations of numeric values to their float equivalents, making it much easier to work with numerical calculations in your applications. Remember to validate your data and handle any potential errors during conversion to maintain robust code.

Feel free to implement these practices in your API handling routines and enhance your Swift programming skills!