restructured code

Author: Rajeev Kumar Singh

tutorial1-hello-world/hello.go renamed to 01-hello-world/hello.go

@@ -3,8 +3,8 @@ package main
 import "fmt"
 
 func main() {
-	var slice1 = []string{"C", "C++", "Java"}
-	var slice2 = append(slice1, "Python", "Ruby", "Go")
+	slice1 := []string{"C", "C++", "Java"}
+	slice2 := append(slice1, "Python", "Ruby", "Go")
 
 	fmt.Printf("slice1 = %v, len = %d, cap = %d\n", slice1, len(slice1), cap(slice1))
 	fmt.Printf("slice2 = %v, len = %d, cap = %d\n", slice2, len(slice2), cap(slice2))

tutorial2-variables/type_inference.go renamed to 02-variables/type_inference.go

@@ -3,10 +3,10 @@ package main
 import "fmt"
 
 func main() {
-	var slice1 = make([]string, 3, 10)
+	slice1 := make([]string, 3, 10)
 	copy(slice1, []string{"C", "C++", "Java"})
 
-	var slice2 = append(slice1, "Python", "Ruby", "Go")
+	slice2 := append(slice1, "Python", "Ruby", "Go")
 
 	fmt.Printf("slice1 = %v, len = %d, cap = %d\n", slice1, len(slice1), cap(slice1))
 	fmt.Printf("slice2 = %v, len = %d, cap = %d\n", slice2, len(slice2), cap(slice2))

tutorial2-variables/variable_declarations.go renamed to 02-variables/variable_declarations.go

@@ -3,10 +3,10 @@ package main
 import "fmt"
 
 func main() {
-	var slice1 = []string{"Jack", "John", "Peter"}
-	var slice2 = []string{"Bill", "Mark", "Steve"}
+	slice1 := []string{"Jack", "John", "Peter"}
+	slice2 := []string{"Bill", "Mark", "Steve"}
 
-	var slice3 = append(slice1, slice2...)
+	slice3 := append(slice1, slice2...)
 
 	fmt.Println("slice1 = ", slice1)
 	fmt.Println("slice2 = ", slice2)

tutorial2-variables/zero_values.go renamed to 02-variables/zero_values.go

@@ -3,7 +3,7 @@ package main
 import "fmt"
 
 func main() {
-	var s = []int{10, 20, 30, 40, 50, 60, 70, 80, 90, 100}
+	s := []int{10, 20, 30, 40, 50, 60, 70, 80, 90, 100}
 	fmt.Println("Original Slice")
 	fmt.Printf("s = %v, len = %d, cap = %d\n", s, len(s), cap(s))
 

tutorial3-basic-types/boolean_types.go renamed to 03-basic-types/boolean_types.go

@@ -3,10 +3,10 @@ package main
 import "fmt"
 
 func main() {
-	var src = []string{"Sublime", "VSCode", "IntelliJ", "Eclipse"}
-	var dest = make([]string, 2)
+	src := []string{"Sublime", "VSCode", "IntelliJ", "Eclipse"}
+	dest := make([]string, 2)
 
-	var numElementsCopied = copy(dest, src)
+	numElementsCopied := copy(dest, src)
 
 	fmt.Println("src = ", src)
 	fmt.Println("dest = ", dest)

tutorial3-basic-types/characters.go renamed to 03-basic-types/characters.go

@@ -3,12 +3,12 @@ package main
 import "fmt"
 
 func main() {
-	var a = [5]string{"C", "C++", "Java", "Python", "Go"}
+	a := [5]string{"C", "C++", "Java", "Python", "Go"}
 
-	var slice1 = a[1:4]
-	var slice2 = a[:3]
-	var slice3 = a[2:]
-	var slice4 = a[:]
+	slice1 := a[1:4]
+	slice2 := a[:3]
+	slice3 := a[2:]
+	slice4 := a[:]
 
 	fmt.Println("Array a = ", a)
 	fmt.Println("slice1 = ", slice1)

tutorial3-basic-types/complex_numbers.go renamed to 03-basic-types/complex_numbers.go

@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	countries := []string{"India", "America", "Russia", "England"}
+
+	for i := 0; i < len(countries); i++ {
+		fmt.Println(countries[i])
+	}
+}

tutorial3-basic-types/integers.go renamed to 03-basic-types/integers.go

@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	primeNumbers := []int{2, 3, 5, 7, 11, 13, 17, 19, 23, 29}
+
+	for index, number := range primeNumbers {
+		fmt.Printf("PrimeNumber(%d) = %d\n", index+1, number)
+	}
+}

tutorial3-basic-types/numeric_operations.go renamed to 03-basic-types/numeric_operations.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	numbers := []float64{3.5, 7.4, 9.2, 5.4}
+
+	sum := 0.0
+	for _, number := range numbers {
+		sum += number
+	}
+
+	fmt.Printf("Total Sum = %.2f\n", sum)
+}

tutorial3-basic-types/strings.go renamed to 03-basic-types/strings.go

@@ -3,8 +3,8 @@ package main
 import "fmt"
 
 func main() {
-	var a = [6]int{10, 20, 30, 40, 50, 60}
-	var s = a[1:4]
+	a := [6]int{10, 20, 30, 40, 50, 60}
+	s := a[1:4]
 
 	fmt.Printf("s = %v, len = %d, cap = %d\n", s, len(s), cap(s))
 }

tutorial3-basic-types/type_conversions.go renamed to 03-basic-types/type_conversions.go

@@ -4,6 +4,6 @@ import "fmt"
 
 func main() {
 	// Creates an array of size 10, slices it till index 5, and returns the slice reference
-	var s = make([]int, 5, 10)
+	s := make([]int, 5, 10)
 	fmt.Printf("s = %v, len = %d, cap = %d\n", s, len(s), cap(s))
 }

tutorial4-constants/constants.go renamed to 04-constants/constants.go

@@ -3,10 +3,10 @@ package main
 import "fmt"
 
 func main() {
-	var a = [7]string{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"}
+	a := [7]string{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"}
 
-	var slice1 = a[1:]
-	var slice2 = a[3:]
+	slice1 := a[1:]
+	slice2 := a[3:]
 
 	fmt.Println("------- Before Modifications -------")
 	fmt.Println("a  = ", a)

tutorial5-control-flow/for-break.go renamed to 05-control-flow/for-break.go

@@ -3,7 +3,7 @@ package main
 import "fmt"
 
 func main() {
-	var s = [][]string{
+	s := [][]string{
 		{"James Smith", "United States"},
 		{"Maria Gracia", "England"},
 		{"Sarah Johnson", "France"},

tutorial5-control-flow/for-continue.go renamed to 05-control-flow/for-continue.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	cities := []string{"New York", "London", "Chicago", "Beijing", "Delhi", "Mumbai", "Bangalore", "Hyderabad", "Hong Kong"}
+
+	asianCities := cities[3:]
+	indianCities := asianCities[1:5]
+
+	fmt.Println("cities = ", cities)
+	fmt.Println("asianCities = ", asianCities)
+	fmt.Println("indianCities = ", indianCities)
+}

tutorial5-control-flow/for-infinite.go renamed to 05-control-flow/for-infinite.go

@@ -0,0 +1,8 @@
+package main
+
+func main() {
+	var x = 67
+	var p = &x
+
+	var p1 = p + 1 // Compiler Error: invalid operation
+}

tutorial5-control-flow/for-without-increment.go renamed to 05-control-flow/for-without-increment.go

@@ -0,0 +1,9 @@
+package main
+
+import "fmt"
+
+func main() {
+	var p *int
+
+	fmt.Println("p = ", p)
+}

tutorial5-control-flow/for-without-init.go renamed to 05-control-flow/for-without-init.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a = 100
+	var p = &a
+
+	fmt.Println("a = ", a)
+	fmt.Println("p = ", p)
+	fmt.Println("*p = ", *p)
+}

tutorial5-control-flow/for.go renamed to 05-control-flow/for.go

@@ -0,0 +1,15 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a = 1000
+	var p = &a
+
+	fmt.Println("a (before) = ", a)
+
+	// Changing the value stored in the pointed variable through the pointer
+	*p = 2000
+
+	fmt.Println("a (after) = ", a)
+}

tutorial5-control-flow/if-else-if.go renamed to 05-control-flow/if-else-if.go

@@ -0,0 +1,14 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a = 75
+	var p1 = &a
+	var p2 = &a
+
+	if p1 == p2 {
+		fmt.Println("Both pointers p1 and p2 point to the same variable.")
+	}
+
+}

tutorial5-control-flow/if-else.go renamed to 05-control-flow/if-else.go

@@ -0,0 +1,12 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a = 5.67
+	var p = &a
+
+	fmt.Println("Value stored in variable a = ", a)
+	fmt.Println("Address of variable a = ", &a)
+	fmt.Println("Value stored in variable p = ", p)
+}

tutorial5-control-flow/if.go renamed to 05-control-flow/if.go

@@ -0,0 +1,21 @@
+package main
+
+import "fmt"
+
+func main() {
+	var a = 7.98
+	var p = &a
+	var pp = &p
+
+	fmt.Println("a = ", a)
+	fmt.Println("address of a = ", &a)
+
+	fmt.Println("p = ", p)
+	fmt.Println("address of p = ", &p)
+
+	fmt.Println("pp = ", pp)
+
+	// Dereferencing a pointer to pointer
+	fmt.Println("*pp = ", *pp)
+	fmt.Println("**pp = ", **pp)
+}

tutorial5-control-flow/switch-combine-cases.go renamed to 05-control-flow/switch-combine-cases.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func getStockPriceChange(prevPrice, currentPrice float64) (float64, float64) {
+	change := currentPrice - prevPrice
+	percentChange := (change / prevPrice) * 100
+	return change, percentChange
+}
+
+func main() {
+	prevStockPrice := 80000.0
+	currentStockPrice := 120000.0
+
+	change, _ := getStockPriceChange(prevStockPrice, currentStockPrice)
+
+	if change < 0 {
+		fmt.Printf("The Stock Price decreased by $%.2f\n", math.Abs(change))
+	} else {
+		fmt.Printf("The Stock Price increased by $%.2f\n", change)
+	}
+}

tutorial5-control-flow/switch-with-no-expression.go renamed to 05-control-flow/switch-with-no-expression.go

@@ -0,0 +1,16 @@
+package main
+
+import "fmt"
+
+func avg(x float64, y float64) float64 {
+	return (x + y) / 2
+}
+
+func main() {
+	x := 5.75
+	y := 6.25
+
+	result := avg(x, y)
+
+	fmt.Printf("Average of %.2f and %.2f = %.2f\n", x, y, result)
+}

tutorial5-control-flow/switch.go renamed to 05-control-flow/switch.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"math"
+)
+
+func getStockPriceChangeWithError(prevPrice, currentPrice float64) (float64, float64, error) {
+	if prevPrice == 0 {
+		err := errors.New("Previous price cannot be zero")
+		return 0, 0, err
+	}
+	change := currentPrice - prevPrice
+	percentChange := (change / prevPrice) * 100
+	return change, percentChange, nil
+}
+
+func main() {
+	prevStockPrice := 0.0
+	currentStockPrice := 100000.0
+
+	change, percentChange, err := getStockPriceChangeWithError(prevStockPrice, currentStockPrice)
+
+	if err != nil {
+		fmt.Println("Sorry! There was an error: ", err)
+	} else {
+		if change < 0 {
+			fmt.Printf("The Stock Price decreased by $%.2f which is %.2f%% of the prev price\n", math.Abs(change), math.Abs(percentChange))
+		} else {
+			fmt.Printf("The Stock Price increased by $%.2f which is %.2f%% of the prev price\n", change, percentChange)
+		}
+	}
+}

tutorial6-arrays/array.go renamed to 06-arrays/array.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+func getStockPriceChange(prevPrice, currentPrice float64) (float64, float64) {
+	change := currentPrice - prevPrice
+	percentChange := (change / prevPrice) * 100
+	return change, percentChange
+}
+
+func main() {
+	prevStockPrice := 0.0
+	currentStockPrice := 100000.0
+
+	change, percentChange := getStockPriceChange(prevStockPrice, currentStockPrice)
+
+	if change < 0 {
+		fmt.Printf("The Stock Price decreased by $%.2f which is %.2f%% of the prev price\n", math.Abs(change), math.Abs(percentChange))
+	} else {
+		fmt.Printf("The Stock Price increased by $%.2f which is %.2f%% of the prev price\n", change, percentChange)
+	}
+}