push all exercices

ch5/1/ch5_1.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+func simpleCalculator(dividend, divisor int) (int, error) {
+	if divisor == 0 {
+		err := errors.New("division by zero")
+		return 0, err
+	}
+	return dividend / divisor, nil
+}
+
+func main() {
+	fmt.Println(simpleCalculator(5, 2))
+	fmt.Println(simpleCalculator(5, 0))
+	fmt.Println(simpleCalculator(17, 6))
+}

ch5/1/go.mod

@@ -0,0 +1,3 @@
+module ch5_1
+
+go 1.25.0

ch5/2/ch5_2.go

@@ -0,0 +1,44 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"os"
+)
+
+func fileLen(filename string) (int, error) {
+	const blockSize = 128
+	file, err := os.Open(filename)
+	if err != nil {
+		fmt.Println("Could not open file!")
+		return 0, err
+	}
+	defer file.Close()
+	dataBlock := make([]byte, blockSize)
+	totalCount := 0
+	for {
+		count, err := file.Read(dataBlock)
+		if err != nil {
+			return 0, err
+		}
+		totalCount += count
+		if count < blockSize {
+			break
+		}
+	}
+	return totalCount, nil
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		err := errors.New("Program doesn't have any arguments. Please pass argument")
+		fmt.Println(err)
+		return
+	}
+	fileSize, err := fileLen(os.Args[1])
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println(fileSize)
+}

ch5/2/go.mod

@@ -0,0 +1,3 @@
+module ch5_2
+
+go 1.25.0

ch5/3/ch5_3.go

@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+func prefixer(prefix string) func(string) string {
+	return func(s string) string { return prefix + " " + s }
+}
+
+func main() {
+	helloPrefix := prefixer("Hello")
+	fmt.Println(helloPrefix("Bob"))   // should print Hello Bob
+	fmt.Println(helloPrefix("Maria")) // should print Hello Maria
+}

ch5/3/go.mod

@@ -0,0 +1,3 @@
+module ch5_3
+
+go 1.25.0