126 lines
3.3 KiB
Go
126 lines
3.3 KiB
Go
// For more tutorials: https://blog.learngoprogramming.com
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//
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// Copyright © 2018 Inanc Gumus
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// Learn Go Programming Course
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// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
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//
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package main
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import (
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s "github.com/inancgumus/prettyslice"
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)
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func main() {
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// ########################################################
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//
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// #1: Create a string slice: `names` with a length and
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// capacity of 5, and print it.
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//
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names := make([]string, 5)
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s.Show("1st step", names)
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// ########################################################
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//
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// #2: Append the following names to the names slice:
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//
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// "einstein", "tesla", "aristo"
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//
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// Print the names slice.
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//
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// Observe how the slice and its backing array change.
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//
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names = append(names, "einstein", "tesla", "aristo")
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s.Show("2nd step", names)
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// ########################################################
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//
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// #3: The previous code appends at the end of the names
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// slice:
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//
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// ["" "" "" "" "" "einstein", "tesla", "aristo"]
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//
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// Append the new elements to the beginning of the names
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// slice instead:
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//
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// ["einstein", "tesla", "aristo" "" ""]
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//
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// So: Overwrite and print the names slice.
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//
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names = make([]string, 0, 5)
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names = append(names, "einstein", "tesla", "aristo")
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s.Show("3rd step", names)
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// ########################################################
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//
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// #4: Copy only the first two elements of the following
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// array to the last two elements of the `names` slice.
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//
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// Print the names slice, you should see 5 elements.
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// So, do not forget extending the slice.
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//
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// Observe how its backing array stays the same.
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//
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moreNames := [...]string{"plato", "khayyam", "ptolemy"}
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copy(names[3:5], moreNames[:2])
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names = names[:cap(names)]
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s.Show("4th step", names)
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// ########################################################
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//
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// #5: Only copy the last 3 elements of the `names` slice
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// to a new slice: `clone`.
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//
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// Append the first two elements of the `names` to the
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// `clone`.
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//
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// Ensure that after appending no new backing array
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// allocations occur for the `clone` slice.
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//
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// Print the clone slice before and after the append.
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//
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clone := make([]string, 3, 5)
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copy(clone, names[len(names)-3:])
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s.Show("5th step (before append)", clone)
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clone = append(clone, names[:2]...)
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s.Show("5th step (after append)", clone)
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// ########################################################
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//
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// #6: Slice the `clone` slice between 2nd and 4th (inclusive)
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// elements into a new slice: `sliced`.
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//
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// Append "hypatia" to the `sliced`.
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//
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// Ensure that new backing array allocation "occurs".
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//
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// Change the 3rd element of the `clone` slice
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// to "elder".
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//
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// Doing so should not change any elements of
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// the `sliced` slice.
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//
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// Print the `clone` and `sliced` slices.
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//
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//
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sliced := clone[1:4:4]
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sliced = append(sliced, "hypatia")
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clone[2] = "elder"
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s.Show("6th step", clone, sliced)
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}
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//
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// Don't mind about this function.
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//
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// For printing the slices: You can either use the
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// prettyslice package or `fmt.Printf`.
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//
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func init() {
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s.PrintBacking = true // prints the backing array
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s.MaxPerLine = 10 // prints 10 slice elements per line
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s.Width = 60 // prints 60 character per line
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}
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