go/src/pkg/bytes/example_test.go

// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package bytes_test

import (
	"bytes"
	"encoding/base64"
	"fmt"
	"io"
	"os"
	"sort"
)

func ExampleBuffer() {
	var b bytes.Buffer // A Buffer needs no initialization.
	b.Write([]byte("Hello "))
	fmt.Fprintf(&b, "world!")
	b.WriteTo(os.Stdout)
	// Output: Hello world!
}

func ExampleBuffer_reader() {
	// A Buffer can turn a string or a []byte into an io.Reader.
	buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
	dec := base64.NewDecoder(base64.StdEncoding, buf)
	io.Copy(os.Stdout, dec)
	// Output: Gophers rule!
}

func ExampleCompare() {
	// Interpret Compare's result by comparing it to zero.
	var a, b []byte
	if bytes.Compare(a, b) < 0 {
		// a less b
	}
	if bytes.Compare(a, b) <= 0 {
		// a less or equal b
	}
	if bytes.Compare(a, b) > 0 {
		// a greater b
	}
	if bytes.Compare(a, b) >= 0 {
		// a greater or equal b
	}

	// Prefer Equal to Compare for equality comparisons.
	if bytes.Equal(a, b) {
		// a equal b
	}
	if !bytes.Equal(a, b) {
		// a not equal b
	}
}

func ExampleCompare_search() {
	// Binary search to find a matching byte slice.
	var needle []byte
	var haystack [][]byte // Assume sorted
	i := sort.Search(len(haystack), func(i int) bool {
		// Return haystack[i] >= needle.
		return bytes.Compare(haystack[i], needle) >= 0
	})
	if i < len(haystack) && bytes.Equal(haystack[i], needle) {
		// Found it!
	}
}