The error Data Type
Let’s learn about the error data type.
We begin with the error
data type because errors play a key role in Go.
Go provides a special data type for representing error conditions and error messages named error
—in practice, this means that Go treats errors as values. In order to program successfully in Go, we should be aware of the error conditions that might occur with the functions and methods we are using and handle them accordingly.
The next convention for error
messages
As we already know, Go follows the next convention about error
values: if the value of an error
variable is nil
, then there was no error.
Example
As an example, let’s consider strconv.Atoi()
, which is used for converting a string
value into an int
value (Atoi
stands for ASCII to Int). As specified by its signature, strconv.Atoi()
returns (int, error)
. Having an error
value of nil
means that the conversion was successful and that we can use the int
value if we want. Having an error
value that is not nil
means that the conversion was unsuccessful and that the string
input is not a valid int
value.
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