Go Struct Tags

Introduction to Go Struct Tags

In Go, struct tags provide a way to attach metadata to struct fields. This metadata is commonly used for purposes such as JSON serialization, database interaction, and validation. Struct tags are a string literal placed immediately after a struct field, encapsulated in backticks.

Using Struct Tags for JSON Mapping

Struct tags are often used to specify how struct fields are encoded to or decoded from JSON. By default, Go uses the field name as the JSON key, but tags allow you to customize this behavior.

Database Mapping with Struct Tags

Struct tags are also useful for database operations. Libraries like GORM use struct tags to map struct fields to database columns. This allows you to specify column names, types, and constraints directly in your struct definition.

Custom Tags for Validation

Another powerful use of struct tags is for validation. Libraries like go-playground/validator utilize struct tags to apply validation rules to struct fields. This can help ensure data integrity and business rule adherence.

Conclusion

Go struct tags are a versatile tool that allow developers to specify additional metadata for struct fields. They play a crucial role in JSON serialization, database mapping, and data validation. Understanding and effectively using struct tags can enhance the functionality and maintainability of your Go applications.