Stringer is the fmt convention satisfied by any type with a parameterless String() string method. Formatting and printing functions use that method to obtain the value’s native textual representation. section 5.2.1 section 6.4.3
Formatting a domain value
A currency can expose its code through String(): func (c Currency) String() string { return c.code } Passing a Currency to fmt.Print* functions then prints its code. Decimal can use the same convention to handle zero precision and pad fractional digits; Amount can combine the formatted number and currency code. section 6.4.3
Use Stringer when:
- A value needs a readable default representation for fmt printing. section 5.2.1
- A type’s textual form should be reusable without adding custom formatting knowledge for callers. section 5.2.1
- A composite value should delegate formatting to its component values, as feedback does for each hint. section 5.2.1
type Stringer interface {
String() string
}
The complete interface declaration makes the required method shape explicit. section 6.4.3
