Sprintf Format Verb Mismatch

Why This Happens

Go's vet tool checks that format verbs in printf-style functions match the types of the corresponding arguments. Using %d with a string or %s with an int is a bug. Use %v as a safe default that works with any type.

The Problem

func main() {
    name := "Alice"
    age := 30
    fmt.Sprintf("Name: %d, Age: %s", name, age) // verbs swapped
}

The Fix

func main() {
    name := "Alice"
    age := 30
    fmt.Sprintf("Name: %s, Age: %d", name, age)
}

Step-by-Step Fix

1. 1

   Identify the mismatch

   Read the vet error to see which format verb does not match which argument.

2. 2

   Fix the verb

   Change the format verb to match the argument type: %s for string, %d for int, %f for float, %v for any.

3. 3

   Run go vet

   Run go vet ./... to catch other printf-style format mismatches.