diff --git a/hacking-go/learn02/casting/casting.go b/hacking-go/learn02/casting/casting.go
new file mode 100644
index 0000000..fc13adb
--- /dev/null
+++ b/hacking-go/learn02/casting/casting.go
@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	var a, b int = 20, 30
+	// Need to convert a and b to float32 before the division
+	var div float32 = float32(a) / float32(b)
+	var divs float32 = float32(a/b)
+	// Cast float32 to int
+	var divInt = int(div)
+	fmt.Println(div, divInt, divs)
+}
diff --git a/hacking-go/learn02/variables/variables.go b/hacking-go/learn02/variables/variables.go
index de34469..13341a6 100644
--- a/hacking-go/learn02/variables/variables.go
+++ b/hacking-go/learn02/variables/variables.go
@@ -16,6 +16,9 @@ func main() {
 	var sampleString_single = "Hello tainguyen"
 
 	fmt.Println("value variable is: ", a, b, d, f, sampleInt, sampleBoolean, sampleString)
+	fmt.Println(a, b, d, f, sampleInt, sampleBoolean, sampleString)
+
 	fmt.Println("value variable single is: ", sampleInt_single, sampleBoolean_single, sampleString_single)
+	fmt.Println(sampleInt_single, sampleBoolean_single, sampleString_single)
 
 }
diff --git a/hacking-go/learn02/variables/variables02.go b/hacking-go/learn02/variables/variables02.go
new file mode 100644
index 0000000..5bd6587
--- /dev/null
+++ b/hacking-go/learn02/variables/variables02.go
@@ -0,0 +1,17 @@
+package main
+
+import "fmt"
+
+func main() {
+	var (
+		sampleInt     = 500
+		sampleBoolean = true
+		sampleString  = "Hello"
+	)
+
+	sampleInt1, sampleBoolean1, sampleString1 := 4000, true, "Hello Tai Nguyen"
+
+	fmt.Println(sampleInt, sampleBoolean, sampleString)
+	fmt.Println(sampleInt1, sampleBoolean1, sampleString1)
+
+}
diff --git a/hacking-go/learn03/constants/constants.go b/hacking-go/learn03/constants/constants.go
new file mode 100644
index 0000000..1979b91
--- /dev/null
+++ b/hacking-go/learn03/constants/constants.go
@@ -0,0 +1,20 @@
+package main
+
+import "fmt"
+
+const Whatever = "whatever"
+const helloworld = "Hello World"
+
+const (
+	Const1 = "Constant String"
+	Int1   = 12345
+	True   = true
+)
+
+func main() {
+	fmt.Println(Whatever)
+	const One = 1
+	fmt.Println(One)
+	fmt.Println(helloworld)
+	fmt.Println(Const1, Int1, True)
+}
diff --git a/hacking-go/learn03/rawstring/rawstring.go b/hacking-go/learn03/rawstring/rawstring.go
new file mode 100644
index 0000000..d3d7052
--- /dev/null
+++ b/hacking-go/learn03/rawstring/rawstring.go
@@ -0,0 +1,38 @@
+package main
+
+import "fmt"
+
+func main() {
+	rawstr :=
+		`First line
+some new lines
+more new lines
+"double quotes"
+`
+	fmt.Print(rawstr)
+
+	rawstr1 :=
+		`one line
+two line
+three line
+"fours line"
+`
+
+	fmt.Print(rawstr1)
+
+	rawstr2 :=
+		`Line with tab	here
+Line with newline
+and more lines
+`
+
+	fmt.Print(rawstr2)
+
+	rawstr3 :=
+		`This is a raw string with backticks: 
+	It spans multiple lines and includes "quotes" and \backslashes\.
+`
+
+	fmt.Print(rawstr3)
+
+}
diff --git a/hacking-go/learn04/for/forloop1.go b/hacking-go/learn04/for/forloop1.go
new file mode 100644
index 0000000..cff3bfa
--- /dev/null
+++ b/hacking-go/learn04/for/forloop1.go
@@ -0,0 +1,30 @@
+package main
+
+import "fmt"
+
+func main() {
+
+	// var sum int
+	sum := 0
+	for i := 0; i < 10; i++ {
+		sum += i
+	}
+	fmt.Println(sum)
+
+	// // var sum int
+	sum1, i1 := 0, 0
+	for i1 < 30 {
+		sum1 += i1
+		i1++
+	}
+
+	fmt.Println(sum1)
+
+	// // var sum int
+	sum2 := 1
+	for i2 := 0; i2 < 40; i2++ {
+		sum2 += i2
+	}
+	fmt.Println(sum2)
+
+}
diff --git a/hacking-go/learn04/for/incdec.go b/hacking-go/learn04/for/incdec.go
new file mode 100644
index 0000000..183f8a1
--- /dev/null
+++ b/hacking-go/learn04/for/incdec.go
@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+func main() {
+
+	// var sum int
+	sum, i := 0, 0
+	// This will not work
+	sum = i++
+
+	fmt.Println(sum)
+}
diff --git a/hacking-go/learn04/if/if.go b/hacking-go/learn04/if/if.go
new file mode 100644
index 0000000..106a453
--- /dev/null
+++ b/hacking-go/learn04/if/if.go
@@ -0,0 +1,19 @@
+package main
+
+import "fmt"
+
+func main() {
+	a := 20
+	b := 20
+
+	if b > a {
+
+		fmt.Println(b, ">", a)
+	}
+	if b < a {
+		fmt.Println(b, "<", a)
+	}
+	if b == a {
+		fmt.Println(b, "=", a)
+	}
+}
diff --git a/hacking-go/learn04/if/if2.go b/hacking-go/learn04/if/if2.go
new file mode 100644
index 0000000..5f76221
--- /dev/null
+++ b/hacking-go/learn04/if/if2.go
@@ -0,0 +1,11 @@
+package main
+
+import "fmt"
+
+func main() {
+	if var1 := 100; var1 > 20 {
+		fmt.Println("Value inside if:", var1)
+	}
+	// Cannot use the variable var1 here
+
+}
diff --git a/hacking-go/learn04/if/ifelse.go b/hacking-go/learn04/if/ifelse.go
new file mode 100644
index 0000000..a0fb799
--- /dev/null
+++ b/hacking-go/learn04/if/ifelse.go
@@ -0,0 +1,13 @@
+package main
+
+import "fmt"
+
+func main() {
+	if var1 := 10; var1 > 20 {
+		fmt.Println("Value inside if:", var1)
+	} else {
+		// Can use var1 here
+		fmt.Println("Value inside else:", var1)
+	}
+
+}