Why Does Go Allow Compilation with Unused Function Parameters but Not Unused Variables?

Why Go Allows Compilation with Unused Parameters in Functions

When transitioning from C to Go, one notable difference is that Go prohibits compilation with unused variables within functions. However, this rule seemingly contradicts the successful compilation of the following code with an unused function parameter:

func main() {
    print(computron(3, -3));
}

func computron(param_a int, param_b int) int {
    return 3 * param_a;
}

Despite the absence of an official explanation, a rationale provided by a Go contributor suggests:

• Programming error prevention: Unused variables are inherently problematic, while unused function parameters are commonplace for various reasons.
• Clear documentation: Unused parameter names contribute to function documentation, even if they are not utilized in the function's code.

Another use case for unused parameters is in implementing interfaces. For example, a uniform-weight graph function can disregard node values:

func (graph *MyGraph) Distance(node1,node2 Node) int {
    return 1
}

While a case can be made for restricting unused parameters to only those named as "_", the Go 1 future-compatibility guarantee precludes such a change. Additionally, unused parameters provide implicit documentation, facilitating comprehension and maintenance of the codebase.

In summary, the lack of a concrete reason suggests that Go's decision to permit compilation with unused function parameters was based on a reasoned, albeit arbitrary, judgment that they are more valuable than prohibiting their presence.

The above is the detailed content of Why Does Go Allow Compilation with Unused Function Parameters but Not Unused Variables?. For more information, please follow other related articles on the PHP Chinese website!