Tutorial4 - Arrays, Slices, Maps and Loops

Author: Shikha-code36

README.md

@@ -45,3 +45,4 @@ go run tutorial1/main.go
 - [x] [Basics](tutorial1)
 - [x] [Constants Variables and Basic Data Types](tutorial2)
 - [x] [Functions and Control Structures](tutorial3)
+- [x] [Arrays, Slices, Maps and Loops](tutorial4)

tutorial4/README.md

@@ -0,0 +1,109 @@
+# Arrays, Slices, and Control Structures in Go
+
+This will guide you through some basic concepts in Go, including arrays, slices, and control structures. The code we'll be discussing demonstrates these concepts in a simple and understandable way.
+
+## Arrays
+
+In Go, an array is a numbered sequence of elements of a specific length. Here are some ways you can declare an array:
+
+1. Declare an array without initializing elements (all elements get the zero value of the element type):
+
+```go
+var intArr [3]int32
+fmt.Println(intArr[0]) // prints: 0
+```
+
+2. Declare an array and initialize some or all elements:
+
+```go
+var intArr [3]int32
+intArr[1] = 123
+fmt.Println(intArr[0]) // prints: 0
+fmt.Println(intArr[1]) // prints: 123
+```
+
+3. Declare and initialize an array using a literal:
+
+```go
+var intArr [3]int32 = [3]int32{1,2,3}
+// or
+intArr := [3]int32{1,2,3}
+// or let Go figure out the length based on the number of elements
+intArr := [...]int32{1,2,3}
+```
+
+4. Access a range of elements (a slice of the array):
+
+```go
+fmt.Println(intArr[1:3]) // prints: [2 3]
+```
+
+## Slices
+
+A slice is a segment of an array. Slices are indexable and have a length. Unlike arrays, they can be resized. Here's how you can declare a slice:
+
+```go
+var intSlice []int32 = []int32{4,5,6}
+```
+
+You can append elements to a slice using the `append` function:
+
+```go
+intSlice = append(intSlice, 7)
+```
+
+You can also append another slice to a slice:
+
+```go
+var intSlice2 []int32 = []int32{8,9}
+intSlice = append(intSlice, intSlice2...)
+```
+
+The `...` is used to pass the elements of `intSlice2` as separate arguments to the `append` function.
+
+## Maps
+
+A map is an unordered collection of key-value pairs. Here's how you can declare a map:
+
+```go
+var myMap map[string]uint8 = make(map[string]uint8)
+```
+
+You can add elements to the map like this:
+
+```go
+var myMap2 =  map[string]uint8{"Shikha":24, "Sarah":23, "Kanha":1}
+```
+
+## Control Structures
+
+### For Loop
+
+Go has only one looping construct: the `for` loop. The basic `for` loop has three components separated by semicolons: the init statement, the condition expression, and the post statement.
+
+Here's a `for` loop that prints the numbers from 0 to 9:
+
+```go
+for i:=0; i<10; i++ {
+	fmt.Printf("printing number %v \n",i)
+}
+```
+
+### While Loop
+
+Go doesn't have a `while` loop, but you can create one using the `for` loop:
+
+```go
+var i int = 0
+for i<10{
+	fmt.Println(i)
+	i=i+1
+}
+```
+
+This will print the numbers from 0 to 9, just like the previous `for` loop.
+
+
+### Checkout the code
+
+ - [main.go](main.go)

tutorial4/main.go

@@ -0,0 +1,110 @@
+package main
+
+import "fmt"
+
+func main() {
+	// var intArr [3]int32
+	// intArr[1] = 123
+	// fmt.Println((intArr[0]))
+	// fmt.Println(intArr[1:3])
+
+	// fmt.Println(&intArr[0])
+	// fmt.Println(&intArr[1])
+	// fmt.Println(&intArr[2])
+
+	//var intArr [3]int32 = [3]int32{1,2,3}
+	//intArr := [3]int32{1,2,3}
+	intArr := [...]int32{1,2,3}
+	fmt.Println(intArr)
+
+	var intSlice []int32 = []int32{4,5,6}
+	fmt.Printf("The length is %v with capacity %v and the value is %v", len(intSlice), cap(intSlice), intSlice)
+	intSlice = append(intSlice, 7)
+	fmt.Printf("\nThe length is %v with capacity %v and the value is %v", len(intSlice), cap(intSlice), intSlice)
+
+	var intSlice2 []int32 = []int32{8,9}
+	intSlice = append(intSlice, intSlice2...)
+	fmt.Printf("\n for slice 2 %v", intSlice)
+
+	var intSlice3 []int32 = make([]int32, 3, 8)
+	intSlice2 = append(intSlice2, intSlice3...)
+	fmt.Printf("\n for slice 3 %v \n", intSlice2)
+
+	var myMap map[string]uint8 = make(map[string]uint8)
+	fmt.Println(myMap)
+
+	var myMap2 =  map[string]uint8{"Shikha":24, "Sarah":23, "Kanha":1}
+	fmt.Printf("Age of Shikha %v \n",myMap2["Shikha"])
+
+	var age, ok = myMap2["Adam"]
+	if ok{
+		fmt.Printf("The age is %v", age)
+	}else{
+		fmt.Println("Invalid Name")
+	}
+
+	delete(myMap2, "Sarah")
+
+	for name, age:= range myMap2{
+		fmt.Printf("Name: %v, Age:%v \n", name, age)
+	}
+
+	for i , v := range intArr{
+		fmt.Printf("Index: %v, Value: %v\n", i, v)
+	}
+
+	//GO doesn't have while loop but it can be achieved by for loop itself
+
+	var i int = 0
+	for i<10{
+		fmt.Println(i)
+		i=i+1
+	}
+
+	for i:=0; i<10; i++ {
+		fmt.Printf("printing number %v \n",i)
+	}
+
+}
+
+/*
+
+>>>>>>>>>>>>>>>>> go run tutorial4/main.go
+
+O/P ::::::
+
+
+[1 2 3]
+The length is 3 with capacity 3 and the value is [4 5 6]
+The length is 4 with capacity 6 and the value is [4 5 6 7]
+ for slice 2 [4 5 6 7 8 9]
+ for slice 3 [8 9 0 0 0] 
+map[]
+Age of Shikha 24 
+Invalid Name
+Name: Shikha, Age:24 
+Name: Kanha, Age:1 
+Index: 0, Value: 1
+Index: 1, Value: 2
+Index: 2, Value: 3
+0
+1
+2
+3
+4
+5
+6
+7
+8
+9
+printing number 0
+printing number 1
+printing number 2
+printing number 3
+printing number 4
+printing number 5
+printing number 6
+printing number 7
+printing number 8
+printing number 9
+*/