如何将所有行输出到给定的写入器并返回字节数

package main

import (
    "fmt"
    "io"
    "strings"
)

func writeLinesToWriter(lines []string, writer io.Writer) (int, error) {
    var content []byte

    for _, line := range lines {
        content = append(content, []byte(line)...)
        content = append(content, '\n')
    }

    bytesWritten, err := writer.Write(content)
    if err != nil {
        return 0, err
    }

    return bytesWritten, nil
}

func main() {
    lines := []string{"Line 1", "Line 2", "Line 3"}

    writer := &strings.Builder{}
    bytesWritten, err := writeLinesToWriter(lines, writer)
    if err != nil {
        fmt.Println("Error:", err)
        return
    }

    fmt.Printf("Bytes written: %d\n", bytesWritten)
    fmt.Printf("Content written: %s", writer.String())
}