What is a race condition in Go? Provide an example.

Data race (race condition) in Go is a situation where multiple goroutines access the same variable simultaneously without proper synchronization, and at least one of them modifies it. This leads to unpredictable program behavior.

Example of a data race:

package main

import (
    "fmt"
    "time"
)

func main() {
    counter := 0

    for i := 0; i < 1000; i++ {
        go func() {
            counter++ // Unsynchronized modification
        }()
    }

    time.Sleep(time.Second)
    fmt.Println("Counter:", counter) // Result may be less than 1000 due to the race
}

In this example, many goroutines simultaneously increment the counter variable without synchronization, leading to lost updates. To avoid races, use mutexes (sync.Mutex), channels, or other synchronization mechanisms.