The Drawbacks of Using %v for Printing Integers and Strings
While it's permissible to use %v for both integers and strings, it's not recommended as it can lead to unexpected behavior with the "fmt" package.
Understanding the Role of %d and %v
Example with Custom Formatter
Output:
In this example, although we use %v, the String() method of MyInt is invoked as it implements the String() method from the fmt.Stringer interface, resulting in the custom formatting applied to the integer.
Default Formatting Rules for %v
According to the "fmt" package documentation, %v attempts to use the following rules in order:
Potential Issues
Printing integers with %v can potentially lead to confusion when the default formatting overrides the expected %d behavior. For example, when dealing with special types like pointers or complex values, using %v might result in unexpected output.
Conclusion
While %v offers flexibility in formatting, it's generally advisable to use specific verbs like %d for integers and %s for strings to ensure clarity and avoid potential ambiguity.
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