110 lines
2.8 KiB
Go
110 lines
2.8 KiB
Go
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package main
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import "fmt"
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// ---------------------------------------------------------
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// EXERCISE: Observe the length and capacity
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//
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// Follow the instructions inside the code below to
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// gain more intuition about the length and capacity of a slice.
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//
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// ---------------------------------------------------------
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func main() {
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// --- #1 ---
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// 1. create a new slice named: games
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//
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// 2. print the length and capacity of the games slice
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//
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// 3. comment out the games slice
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// then declare it as an empty slice
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//
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// 4. print the length and capacity of the games slice
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//
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// 5. append the elements: "pacman", "mario", "tetris", "doom"
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//
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// 6. print the length and capacity of the games slice
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//
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// 7. comment out everything
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//
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// 8. declare it again using a slice literal
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// (use the same elements from step 3)
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// --- #2 ---
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// 1. use a loop from 0 to 4 to slice the games slice, element by element.
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//
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// 2. print its length and capacity along the way (in the loop).
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fmt.Println()
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// for ... {
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// fmt.Printf("games[:%d]'s len: %d cap: %d\n", ...)
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// }
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// --- #3 ---
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// 1. slice the games slice up to zero element
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// (save the result to a new slice named: "zero")
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//
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// 2. print the games and the new slice's len and cap
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//
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// 3. append a new element to the new slice
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//
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// 4. print the new slice's lens and caps
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//
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// 5. repeat the last two steps 5 times (use a loop)
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//
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// 6. notice the growth of the capacity after the 5th append
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//
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// Use this slice's elements to append to the new slice:
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// []string{"ultima", "dagger", "pong", "coldspot", "zetra"}
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fmt.Println()
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// zero := ...
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// fmt.Printf("games's len: %d cap: %d\n", ...)
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// fmt.Printf("zero's len: %d cap: %d\n", ...)
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// for ... {
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// ...
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// fmt.Printf("zero's len: %d cap: %d\n", ...)
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// }
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// --- #4 ---
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// using a range loop, slice the zero slice element by element,
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// and print its length and capacity along the way.
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//
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// observe that, the range loop only loops for the length, not the cap.
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fmt.Println()
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// for ... {
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// s := zero[:n]
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// fmt.Printf("zero[:%d]'s len: %d cap: %d\n", ...)
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// }
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// --- #5 ---
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// 1. do the 3rd step above again but this time, start by slicing
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// the zero slice up to its capacity (use the cap function).
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//
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// 2. print the elements of the zero slice in the loop.
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fmt.Println()
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// zero = ...
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// for ... {
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// fmt.Printf("zero[:%d]'s len: %d cap: %d - %q\n", ...)
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// }
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// --- #6 ---
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// 1. change the one of the elements of the zero slice
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//
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// 2. change the same element of the games slice
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//
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// 3. print the games and the zero slices
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//
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// 4. observe that they don't have the same backing array
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fmt.Println()
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// ...
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// fmt.Printf("zero : %q\n", zero)
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// fmt.Printf("games : %q\n", games)
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// --- #7 ---
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// try to slice the games slice beyond its capacity
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}
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