github.com/spotify/syslog-redirector-golang@v0.0.0-20140320174030-4859f03d829a/blog/content/slices/prog110.go (about)

     1  // Copyright 2013 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package main
     6  
     7  import (
     8  	"fmt"
     9  )
    10  
    11  // Extend extends the slice by adding the element to the end.
    12  func Extend(slice []int, element int) []int {
    13  	n := len(slice)
    14  	if n == cap(slice) {
    15  		// Slice is full; must grow.
    16  		// We double its size and add 1, so if the size is zero we still grow.
    17  		newSlice := make([]int, len(slice), 2*len(slice)+1)
    18  		copy(newSlice, slice)
    19  		slice = newSlice
    20  	}
    21  	slice = slice[0 : n+1]
    22  	slice[n] = element
    23  	return slice
    24  }
    25  
    26  func main() {
    27  	// START OMIT
    28  	slice := make([]int, 0, 5)
    29  	for i := 0; i < 10; i++ {
    30  		slice = Extend(slice, i)
    31  		fmt.Printf("len=%d cap=%d slice=%v\n", len(slice), cap(slice), slice)
    32  		fmt.Println("address of 0th element:", &slice[0])
    33  	}
    34  	// END OMIT
    35  }