blog/content/slices/prog110.go

// +build OMIT

// Copyright 2013 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 main

import (
	"fmt"
)

// Extend extends the slice by adding the element to the end.
func Extend(slice []int, element int) []int {
	n := len(slice)
	if n == cap(slice) {
		// Slice is full; must grow.
		// We double its size and add 1, so if the size is zero we still grow.
		newSlice := make([]int, len(slice), 2*len(slice)+1)
		copy(newSlice, slice)
		slice = newSlice
	}
	slice = slice[0 : n+1]
	slice[n] = element
	return slice
}

func main() {
	// START OMIT
	slice := make([]int, 0, 5)
	for i := 0; i < 10; i++ {
		slice = Extend(slice, i)
		fmt.Printf("len=%d cap=%d slice=%v\n", len(slice), cap(slice), slice)
		fmt.Println("address of 0th element:", &slice[0])
	}
	// END OMIT
}