已评估但未使用

Question

I'm not sure what's happening here.

I'm working on Project Euler #8 and have come up with the following function to handle getting the product of 5 digits:

func fiveDigitProduct(n int) int {
    localMax := n + 5
    product := 1
    for n; n < localMax; n++ {
        f, _ := strconv.Atoi(input[n])
        product *= f
    }
    return product
}

However, I keep getting the warning "n evaluated but not used". I have no idea why this is happening.

Answer 1

The InitStmt (initialization statement) of your For Statement isn't actually doing any initialization. You're asking the compiler to evaluate n but not do anything with it, which is what the compiler is complaining about. Since you don't need to initialize n for you loop, just do:

for ; n < localMax; n++ {