Initial commit

14-arrays/01-what/01-without-arrays/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	jake := "jake"
+	joe := "joe"
+	lee := "lee"
+	lina := "lina"
+
+	fmt.Println(jake)
+	fmt.Println(joe)
+	fmt.Println(lee)
+	fmt.Println(lina)
+
+	// for each name
+	// you need to declare a variable
+	// and then you need to print it
+	//
+	// but by using an array, you don't need to do that
+}

14-arrays/01-what/02-with-arrays/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	// instead of storing the names in variables,
+	// you can use an array to store all of the names
+	//   in a single variable
+
+	// names := [3]string{"jake", "joe", "lee"}
+	names := [4]string{"jake", "joe", "lee", "lina"}
+
+	// doing so allows you to loop over the names
+	// and print each one of them
+	//
+	// you can't do this without arrays
+	for _, name := range names {
+		fmt.Println(name)
+	}
+}

14-arrays/02-array-literals/01/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [3]int{15, 30, 25}
+
+	for _, age := range ages {
+		fmt.Println(age)
+	}
+}

14-arrays/02-array-literals/02-fixed-size/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+func main() {
+	// uncomment the code below to observe the error
+
+	// ages := [3]int{15, 30, 25, 44}
+
+	// for _, age := range ages {
+	// 	fmt.Println(age)
+	// }
+}

14-arrays/02-array-literals/03-constant-expressions/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	// you cannot use variables
+	// when setting the length of an array
+
+	// length := 3
+
+	// but, you can use constants and constant expressions
+	const length = 3 * 2
+
+	ages := [3 * 2]int{15, 30, 25}
+
+	for _, age := range ages {
+		fmt.Println(age)
+	}
+}
+
+// EXERCISE:
+//   Try to put the `length` constant
+//   in place of `3 * 2` above.
+
+// EXERCISE:
+//   Try to put the `length` variable
+//   in place of `3 * 2` above.
+//
+//   And observe the error.
+//
+//   To do that, you need comment-out
+//   the length constant first.

14-arrays/02-array-literals/04-element-type/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+func main() {
+	// -----
+	// you cannot use incompatible values
+	// than the array's element type
+	//
+	// uncomment the code parts below one by one
+	// then observe the errors
+	// -----
+
+	// for example you can't use a string
+	// ages := [3]int{15, 30, "hi"}
+
+	// -----
+
+	// or a float64, etc...
+	// ages := [3]int{15, 30, 5.5}
+
+	// -----
+
+	// of course this is valid, since it's untyped
+	// 5. becomes 5 (int)
+	// ages := [3]int{15, 30, 5.}
+
+	// -----
+
+	// for _, age := range ages {
+	// 	fmt.Println(age)
+	// }
+}
+
+// EXERCISE:
+//   Try to put the `length` constant
+//   in place of `3 * 2` above.
+
+// EXERCISE:
+//   Try to put the `length` variable
+//   in place of `3 * 2` above.
+//
+//   And observe the error.
+//
+//   To do that, you need comment-out
+//   the length constant first.

14-arrays/02-array-literals/05-ellipsis/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [...]int{15, 30, 25}
+	// equals to:
+	// ages := [3]int{15, 30, 25}
+
+	for _, age := range ages {
+		fmt.Println(age)
+	}
+}

14-arrays/03-array-type/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [3]int{15, 30, 25}
+
+	fmt.Printf("%T\n", ages)                 // [3]int
+	fmt.Printf("%T\n", [...]int{15, 30, 25}) // [3]int
+
+	fmt.Printf("%T\n", [2]int{15, 30}) // [2]int
+
+	fmt.Printf("%T\n", [1]string{"hi"})          // [1]string
+	fmt.Printf("%T\n", [...]float64{3.14, 6.28}) // [2]float64
+}

14-arrays/04-zero-values/01-uninitialized-array/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	var ages [3]int
+
+	fmt.Println(ages)
+}

14-arrays/04-zero-values/02-partially-initialized-array/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [3]int{1}
+
+	fmt.Println(ages)
+}

14-arrays/04-zero-values/03-ellipsis/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	names := [...]string{
+		"lina", "bob", "jane",
+	}
+
+	fmt.Printf("%#v\n", names)
+}

14-arrays/04-zero-values/04-without-ellipsis/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	names := [5]string{
+		"lina", "bob", "jane",
+	}
+
+	fmt.Printf("%#v\n", names)
+}

14-arrays/04-zero-values/05-more-examples/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	names := [5]string{
+		"lina", "bob", "jane",
+	}
+
+	fmt.Printf("%#v\n", names)
+
+	temperatures := [10]float64{1.5, 2.5}
+	fmt.Printf("%#v\n", temperatures)
+}

14-arrays/05-array-operations/01-getting-length/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [2]int{15, 20}
+
+	// i can directly use `len`
+	fmt.Println(len(ages)) // 2
+
+	// i can also assign its result to a variable
+	l := len(ages)
+	fmt.Println(l) // 2
+
+	// let's print the length of a few arrays
+	l = len([1]bool{true}) // 1
+	fmt.Println(l)
+
+	l = len([3]string{"lina", "james", "joe"}) // 3
+	fmt.Println(l)
+
+	// this array doesn't initialize any elements
+	// but its length is still 5
+	// whether the elements are initialized or not
+	l = len([5]int{})
+	fmt.Println(l) // 5
+	fmt.Println([5]int{})
+}

14-arrays/05-array-operations/02-getting-elements/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [2]int{15, 20}
+
+	// WRONG (try it):
+	// fmt.Println(ages[-1])
+
+	fmt.Println("1st item:", ages[0])
+	fmt.Println("2nd item:", ages[1])
+
+	// fmt.Println("2nd item:", ages[2])
+
+	// fmt.Println(ages[len(ages)])
+	// here, `len(ages) - 1` equals to 1
+	fmt.Println("last item:", ages[len(ages)-1])
+
+	// let's display the indexes and the items
+	// of the array
+	for i, v := range ages {
+		fmt.Printf("index: %d, value: %d\n", i, v)
+	}
+}

14-arrays/05-array-operations/03-getting-elements/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	ages := [2]int{15, 20}
+
+	ages[0] = 6
+	ages[1] *= 3
+
+	fmt.Println(ages)
+
+	// increase the last element by 1
+	ages[1]++
+	ages[len(ages)-1]++
+
+	fmt.Println(ages)
+
+	// v is a copy
+	for _, v := range ages {
+		// it's like:
+		// v = ages[0]
+		// v++
+
+		// and:
+		// v = ages[1]
+		// v++
+
+		v++
+	}
+
+	fmt.Println(ages)
+
+	// you don't need to use blank-identifier for the value
+	// for i, _ := range ages {
+
+	for i := range ages {
+		ages[i]++
+	}
+
+	fmt.Println(ages)
+}

14-arrays/06-comparing-arrays/01-equal-arrays/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [3]int{6, 9, 3}
+	b := [3]int{6, 9, 3}
+
+	if a == b {
+		fmt.Println("they're equal!")
+
+		// they're comparable
+		// since their types are identical
+		fmt.Printf("1st array's type is %T\n", a)
+		fmt.Printf("2nd array's type is %T\n", b)
+
+		// go compares arrays like this
+		// it compares the elements one by one
+		fmt.Println(a[0] == b[0])
+		fmt.Println(a[1] == b[1])
+		fmt.Println(a[2] == b[2])
+	}
+}

14-arrays/06-comparing-arrays/02-not-equal-arrays/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [3]int{6, 9, 3}
+	b := [3]int{3, 9, 6}
+
+	if a == b {
+		fmt.Println("they're equal!")
+	} else {
+		fmt.Println("they're not equal! a==b?", a == b)
+
+		// but, they're comparable
+		// since their types are identical
+		fmt.Printf("1st array's type is %T\n", a)
+		fmt.Printf("2nd array's type is %T\n", b)
+
+		// go compares arrays like this
+		// it compares the elements one by one
+		fmt.Println(a[0] == b[0]) // false
+		fmt.Println(a[1] == b[1]) // true
+		fmt.Println(a[2] == b[2]) // false
+
+		// actually Go will quit comparing these arrays
+		//   once it sees unequal items
+		//
+		// so, it will stop the comparison (short-circuit)
+		//   when it sees the first item is false
+		//   and it will return false
+	}
+}

14-arrays/06-comparing-arrays/03-comparability/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+func main() {
+	// these two arrays not comparable
+	// their types are different
+
+	// uncomment all the code below and observe the error
+
+	// a := [3]int{6, 9, 3}
+	// b := [2]int{6, 9}
+
+	// you can't ask this question
+
+	// if a == b {
+	// 	fmt.Println("they're equal!")
+	// }
+}

14-arrays/06-comparing-arrays/04-example/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [2]string{"jane", "lina"}
+	b := [2]string{"jane", "lina"}
+	c := [2]string{"mike", "joe"}
+
+	fmt.Println("a==b?", a == b) // equal
+	fmt.Println("a==c?", a == c) // not equal
+
+	// cannot compare
+	d := [3]string{"jane", "lina"}
+	// fmt.Println("c==d?", c == d)
+
+	fmt.Printf("type of c is %T\n", c)
+	fmt.Printf("type of d is %T\n", d)
+}

14-arrays/07-unnamed-vs-named-types/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	type (
+		A [3]int
+		B [3]int
+	)
+
+	x := A{1, 2, 3}
+	y := B{1, 2, 3}
+	z := [3]int{1, 2, 3}
+
+	fmt.Printf("x's type: %T\n", x) // named type  : main.A
+	fmt.Printf("y's type: %T\n", y) // named type  : main.B
+	fmt.Printf("z's type: %T\n", z) // unnamed type: [3]int
+
+	// cannot compare different named types
+	// fmt.Println("x==y?", x == y)
+
+	// can convert between identical types
+	fmt.Println("x==y?", x == A(y))
+	fmt.Println("x==y?", B(x) == y)
+
+	fmt.Printf("x's type   : %T\n", x)
+	fmt.Printf("A(y)'s type: %T\n", A(y))
+
+	// can compare to unnamed types
+	fmt.Println("x==z?", x == z)
+}

14-arrays/08-assigning-arrays/01-assigning-arrays/main.go

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+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [3]int{5, 4, 7}
+
+	// this assignment will create a new array value
+	// and then it will be stored in the b variable
+	b := a
+
+	fmt.Println("a =>", a)
+	fmt.Println("b =>", b)
+
+	// they're equal, they're clones
+	fmt.Println("a==b?", a == b)
+}

14-arrays/08-assigning-arrays/02-arrays-are-value-types/main.go

@@ -0,0 +1,27 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [3]int{5, 4, 7}
+	b := a
+
+	// this will only change the 'a' array
+	a[0] = 10
+
+	fmt.Println("a =>", a)
+	fmt.Println("b =>", b)
+
+	// this will only change the 'b' array
+	b[1] = 20
+
+	fmt.Println("a =>", a)
+	fmt.Println("b =>", b)
+}

14-arrays/08-assigning-arrays/03-assigning-arrays2/main.go

@@ -0,0 +1,23 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [3]int{5, 4, 7}
+	b := [3]int{6, 9, 3}
+
+	b = a
+
+	fmt.Println("b =>", b)
+
+	b[0] = 100
+	fmt.Println("a =>", a)
+	fmt.Println("b =>", b)
+}

14-arrays/08-assigning-arrays/04-cannot-assign-arrays/main.go

@@ -0,0 +1,23 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+func main() {
+	// you can't assign the array 'a' to the array 'b'
+	// a's type is [2]int whereas b's type is [3]int
+
+	// when two values are not comparable,
+	// then they're not assignable either
+
+	// uncomment and observe the error
+
+	// a := [2]int{5, 4}
+	// b := [3]int{6, 9, 3}
+
+	// b = a
+}

14-arrays/08-assigning-arrays/05-passing-to-funcs/main.go

@@ -0,0 +1,31 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	a := [3]int{10, 4, 7}
+
+	// like the assignment passing an array to a function
+	// creates a copy of the array
+	fmt.Println("a (before) =>", a)
+	incr(a)
+	fmt.Println("a (after)  =>", a)
+}
+
+// inside the function
+// the passed array 'a' is a new copy (a clone)
+// it's not the original one
+func incr(a [3]int) {
+	// this only changes the copy of the passed array
+	a[1]++
+
+	// this prints the copied array not the original one
+	fmt.Println("a (inside) =>", a)
+}

14-arrays/09-multi-dimensional-arrays/main.go

@@ -0,0 +1,49 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	// [LENGTH]TYPE {
+	//   ELEMENTS
+	// }
+
+	// LENGTH=2 and TYPE=[2]int
+
+	// nums := [2][2]int{
+	// 	[2]int{2, 4},
+	// 	[2]int{1, 3},
+	// }
+
+	// code below is the same as the code above
+	nums := [2][2]int{
+		{2, 4},
+		{1, 3},
+	}
+
+	fmt.Println("nums         =", nums)
+	fmt.Println("nums[0]      =", nums[0])
+	fmt.Println("nums[1]      =", nums[1])
+
+	fmt.Println("nums[0][0]   =", nums[0][0])
+	fmt.Println("nums[0][1]   =", nums[0][1])
+	fmt.Println("nums[1][0]   =", nums[1][0])
+	fmt.Println("nums[1][1]   =", nums[1][1])
+
+	fmt.Println("len(nums)    =", len(nums))
+	fmt.Println("len(nums[0]) =", len(nums[0]))
+	fmt.Println("len(nums[1]) =", len(nums[1]))
+
+	for i, array := range nums {
+		for j, n := range array {
+			// nums[i][j] = number
+			fmt.Printf("nums[%d][%d] = %d\n", i, j, n)
+		}
+	}
+}

14-arrays/10-keyed-elements/01-unkeyed/main.go

@@ -0,0 +1,20 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	rates := [3]float64{
+		0.5,
+		2.5,
+		1.5,
+	}
+
+	fmt.Println(rates)
+}

14-arrays/10-keyed-elements/02-keyed/main.go

@@ -0,0 +1,28 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	rates := [3]float64{
+		0: 0.5, // index: 0
+		1: 2.5, // index: 1
+		2: 1.5, // index: 2
+	}
+
+	fmt.Println(rates)
+
+	// above array literal equals to this:
+	//
+	// rates := [3]float64{
+	// 	0.5,
+	// 	2.5,
+	// 	1.5,
+	// }
+}

14-arrays/10-keyed-elements/03-keyed-order/main.go

@@ -0,0 +1,28 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	rates := [3]float64{
+		1: 2.5, // index: 1
+		0: 0.5, // index: 0
+		2: 1.5, // index: 2
+	}
+
+	fmt.Println(rates)
+
+	// above array literal equals to this:
+	//
+	// rates := [3]float64{
+	// 	0.5,
+	// 	2.5,
+	// 	1.5,
+	// }
+}

14-arrays/10-keyed-elements/04-keyed-auto-initialize/main.go

@@ -0,0 +1,28 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	rates := [3]float64{
+		// index 0 empty
+		// index 1 empty
+		2: 1.5, // index: 2
+	}
+
+	fmt.Println(rates)
+
+	// above array literal equals to this:
+	//
+	// rates := [3]float64{
+	// 	0.,
+	// 	0.,
+	// 	1.5,
+	// }
+}

14-arrays/10-keyed-elements/05-keyed-auto-initialize-ellipsis/main.go

@@ -0,0 +1,36 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	// ellipsis (...) below calculates the length of the
+	// array automatically
+	rates := [...]float64{
+		// index 0 empty
+		// index 1 empty
+		// index 2 empty
+		// index 3 empty
+		// index 4 empty
+		5: 1.5, // index: 5
+	}
+
+	fmt.Println(rates)
+
+	// above array literal equals to this:
+	//
+	// rates := [6]float64{
+	// 	0.,
+	// 	0.,
+	// 	0.,
+	// 	0.,
+	// 	0.,
+	// 	1.5,
+	// }
+}

14-arrays/10-keyed-elements/06-keyed-and-unkeyed/main.go

@@ -0,0 +1,34 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	rates := [...]float64{
+		// index 1 to 4 empty
+
+		5:   1.5, // index: 5
+		2.5, //      index: 6
+		0:   0.5, // index: 0
+	}
+
+	fmt.Println(rates)
+
+	// above array literal equals to this:
+	//
+	// rates := [7]float64{
+	// 	0.5,
+	// 	0.,
+	// 	0.,
+	// 	0.,
+	// 	0.,
+	// 	1.5,
+	//  2.5,
+	// }
+}

14-arrays/11-project-xratio/01-without-keys/main.go

@@ -0,0 +1,21 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func main() {
+	rates := [...]float64{
+		25.5,  // ethereum
+		120.5, // wanchain
+	}
+
+	// uses magic values - not good
+	fmt.Printf("1 BTC is %g ETH\n", rates[0])
+	fmt.Printf("1 BTC is %g WAN\n", rates[1])
+}

14-arrays/11-project-xratio/02-with-keys/main.go

@@ -0,0 +1,30 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+// REFACTORED VERSION
+// It uses well-defined names instead of magic numbers.
+// Thanks to keyed elements and constants.
+
+func main() {
+	const (
+		ETH = iota
+		WAN
+	)
+
+	rates := [...]float64{
+		ETH: 25.5,
+		WAN: 120.5,
+	}
+
+	// uses well-defined names (ETH, WAN, ...) - good
+	fmt.Printf("1 BTC is %g ETH\n", rates[ETH])
+	fmt.Printf("1 BTC is %g WAN\n", rates[WAN])
+}

14-arrays/12-random-message/01-1st-version/main.go

@@ -0,0 +1,38 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+)
+
+func main() {
+	args := os.Args[1:]
+	if len(args) != 1 {
+		fmt.Println("[your name]")
+		return
+	}
+
+	name := args[0]
+
+	moods := [...]string{
+		"happy 😀", "good 👍", "awesome 😎",
+		"sad 😞", "bad 👎", "terrible 😩",
+	}
+
+	rand.Seed(time.Now().UnixNano())
+	n := rand.Intn(len(moods))
+
+	fmt.Printf("%s feels %s\n", name, moods[n])
+}
+
+// inspired from:
+// https://github.com/moby/moby/blob/1fd7e4c28d3a4a21c3540f03a045f96a4190b527/pkg/namesgenerator/names-generator.go

14-arrays/12-random-message/02-2nd-version/main.go

@@ -0,0 +1,39 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"time"
+)
+
+func main() {
+	args := os.Args[1:]
+	if len(args) != 2 {
+		fmt.Println("[your name] [positive|negative]")
+		return
+	}
+
+	name, mood := args[0], args[1]
+
+	moods := [...][3]string{
+		{"happy 😀", "good 👍", "awesome 😎"},
+		{"sad 😞", "bad 👎", "terrible 😩"},
+	}
+
+	rand.Seed(time.Now().UnixNano())
+	n := rand.Intn(len(moods[0]))
+
+	var mi int
+	if mood != "positive" {
+		mi = 1
+	}
+	fmt.Printf("%s feels %s\n", name, moods[mi][n])
+}

14-arrays/13-refactor-lucky-number-game/main.go

@@ -0,0 +1,72 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"strconv"
+	"time"
+)
+
+const (
+	maxTurns = 5 // less is more difficult
+	usage    = `Welcome to the Lucky Number Game!
+
+The program will pick %d random numbers.
+Your mission is to guess one of those numbers.
+
+The greater your number is, harder it gets.
+
+Wanna play?
+`
+)
+
+func main() {
+	rand.Seed(time.Now().UnixNano())
+
+	args := os.Args[1:]
+
+	if len(args) != 1 {
+		fmt.Printf(usage, maxTurns)
+		return
+	}
+
+	guess, err := strconv.Atoi(args[0])
+	if err != nil {
+		fmt.Println("Not a number.")
+		return
+	}
+
+	if guess < 0 {
+		fmt.Println("Please pick a positive number.")
+		return
+	}
+
+	// This array will store the generated random numbers
+	var pickeds [maxTurns]int
+
+	for turn := 0; turn < maxTurns; turn++ {
+		n := rand.Intn(guess + 1)
+
+		pickeds[turn] = n
+
+		if n == guess {
+			fmt.Println("🎉  YOU WIN!")
+			goto pickeds
+		}
+	}
+
+	fmt.Println("☠️  YOU LOST... Try again?")
+
+pickeds:
+	fmt.Println("Computer has picked these:", pickeds)
+
+	// after this line the program automatically exits
+}

14-arrays/exercises/00/main.go

@@ -0,0 +1,22 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+// ---------------------------------------------------------
+// EXERCISE
+//  ?
+//
+// NOTE
+//  ?
+//
+// EXPECTED OUTPUT
+//  ?
+// ---------------------------------------------------------
+
+func main() {
+}

14-arrays/exercises/00/solution/main.go

@@ -0,0 +1,11 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+func main() {
+}

14-arrays/exercises/xxx-lucky-number-unique-picker/main.go

@@ -0,0 +1,82 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"os"
+	"strconv"
+	"time"
+)
+
+const (
+	maxTurns = 5 // less is more difficult
+	usage    = `Welcome to the Lucky Number Game!
+
+The program will pick %d random numbers.
+Your mission is to guess one of those numbers.
+
+The greater your number is, harder it gets.
+
+Wanna play?
+`
+)
+
+func main() {
+	rand.Seed(time.Now().UnixNano())
+
+	args := os.Args[1:]
+
+	if len(args) != 1 {
+		fmt.Printf(usage, maxTurns)
+		return
+	}
+
+	guess, err := strconv.Atoi(args[0])
+	if err != nil {
+		fmt.Println("Not a number.")
+		return
+	}
+
+	if guess < 0 {
+		fmt.Println("Please pick a positive number.")
+		return
+	}
+
+	// This array will store the generated random numbers
+	var pickeds [maxTurns]int
+
+	for turn := 0; turn < maxTurns; turn++ {
+		var n int
+	pick:
+		for {
+			n = rand.Intn(guess + 1)
+			for _, v := range pickeds {
+				if n == v {
+					continue pick
+				}
+			}
+			break
+		}
+
+		pickeds[turn] = n
+
+		if n == guess {
+			fmt.Println("🎉  YOU WIN!")
+			goto pickeds
+		}
+	}
+
+	fmt.Println("☠️  YOU LOST... Try again?")
+
+pickeds:
+	fmt.Println("Computer has picked these:", pickeds)
+
+	// after this line the program automatically exits
+}

14-arrays/questions/questions.md

@@ -0,0 +1,3 @@
+## ?
+* text *CORRECT*
+* text