Tutorial10 - Generics

Author: Shikha-code36

README.md

@@ -50,4 +50,5 @@ go run tutorial1/main.go
 - [x] [Structs and Interfaces](tutorial6)
 - [x] [Pointers](tutorial7)
 - [x] [Concurrency(Goroutines)](tutorial8)
-- [x] [Channels](tutorial9)
+- [x] [Channels](tutorial9)
+- [x] [Generics](tutorial10)

tutorial10/README.md

@@ -0,0 +1,88 @@
+# Generics in GO
+
+## Key Concepts
+
+### Generics
+
+Generics is a concept in programming where a function or a data type can be written in a way that it can handle different data types. In Go, generics are defined using square brackets `[]` followed by a type parameter list.
+
+### Generic Functions
+
+In this program, we have three generic functions: `sumSlice`, `isEmpty`, and `LoadJSON`.
+
+```go
+func sumSlice[T int | float32 | float64](slice []T) T{
+    var sum T
+    for _, v := range slice{
+        sum += v
+    }
+    return sum
+}
+
+func isEmpty[T any](slice []T) bool{
+    return len(slice) == 0
+}
+
+func LoadJSON[T contactInfo | purchaseInfo] (filePath string) []T{
+    data, _ := ioutil.ReadFile(filePath)    
+    var loaded = []T{}  
+    json.Unmarshal(data, &loaded)
+
+    return  loaded
+}
+```
+
+`sumSlice` takes a slice of type `T` where `T` can be `int`, `float32`, or `float64`. It returns the sum of all elements in the slice.
+
+`isEmpty` takes a slice of any type `T` and returns a boolean indicating whether the slice is empty.
+
+`LoadJSON` takes a file path as input and returns a slice of type `T` where `T` can be `contactInfo` or `purchaseInfo`. It reads the JSON file from the given file path and unmarshals the data into a slice of the appropriate type.
+
+### Generic Structs
+
+In this program, we have two struct types: `contactInfo` and `purchaseInfo`.
+
+```go
+type contactInfo struct{
+    Name string 
+    Email string    
+}
+    
+type purchaseInfo struct{   
+    Name string
+    Price float32
+    Amount int
+}
+```
+
+These structs are used as type parameters in the `LoadJSON` function to load JSON data of different types.
+
+## Usage
+
+In the `main` function, we demonstrate the usage of these generic functions.
+
+```go
+func main(){
+    var intSlice = []int{1,2,3}
+    fmt.Println(sumSlice[int](intSlice))
+
+    var float32Slice = []float32{1,2,3}
+    fmt.Println(sumSlice[float32](float32Slice))
+
+    var sliceint = []int{}
+    fmt.Println(isEmpty[int](sliceint))
+    fmt.Println(isEmpty[int](intSlice))
+
+    var contacts []contactInfo = LoadJSON[contactInfo]("./files/contactInfo.json")
+    fmt.Printf("\n%+v", contacts)
+
+    var purchases []purchaseInfo = LoadJSON [purchaseInfo]("./files/PurchaseInfo.json")
+    fmt.Printf("\n%+v", purchases)
+}
+```
+
+We create slices of `int` and `float32` and use `sumSlice` to calculate their sums. We also check if a slice is empty using `isEmpty`. Finally, we use `LoadJSON` to load JSON data into slices of `contactInfo` and `purchaseInfo`.
+
+### Checkout the code
+
+- [main.go](main.go)

tutorial10/files/contactInfo.json

@@ -0,0 +1,10 @@
+[
+    {
+        "name": "Alex",
+        "Email": "sp@gmail.com"
+    },
+    {
+        "name": "Jason",
+        "number": "jas@gmail.com"
+    }
+]

tutorial10/files/purchaseInfo.json

@@ -0,0 +1,12 @@
+[
+    {
+        "name": "Alex",
+        "price": 19.99,
+        "amount": 3
+    },
+    {
+        "name": "Jason",
+        "price": 29.99,
+        "amount": 1
+    }
+]

tutorial10/main.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"fmt"
+	"encoding/json"
+	"io/ioutil"
+)
+
+type contactInfo struct{
+	Name string	
+	Email string	
+}
+	
+type purchaseInfo struct{	
+	Name string
+	Price float32
+	Amount int
+}
+
+func main(){
+	var intSlice = []int{1,2,3}
+	fmt.Println(sumSlice[int](intSlice))
+
+	var float32Slice = []float32{1,2,3}
+	fmt.Println(sumSlice[float32](float32Slice))
+
+	var sliceint = []int{}
+	fmt.Println(isEmpty[int](sliceint))
+	fmt.Println(isEmpty[int](intSlice))
+
+	var contacts []contactInfo = LoadJSON[contactInfo]("./files/contactInfo.json")
+	fmt.Printf("\n%+v", contacts)
+
+	var purchases []purchaseInfo = LoadJSON [purchaseInfo]("./files/PurchaseInfo.json")
+	fmt.Printf("\n%+v", purchases)
+	}
+
+func sumSlice[T int | float32 | float64](slice []T) T{
+	var sum T
+	for _, v := range slice{
+		sum += v
+	}
+	return sum
+}
+
+// we can do type any because not all types are compaitible with + operators
+
+func isEmpty[T any](slice []T) bool{
+	return len(slice) == 0
+}
+
+func LoadJSON[T contactInfo | purchaseInfo] (filePath string) []T{
+	data, _ := ioutil.ReadFile(filePath)	
+	var loaded = []T{}	
+	json.Unmarshal(data, &loaded)
+
+	return  loaded
+}
+
+/*
+>>>>>>>>>>>>>>>>>>>>>>> go run tutorial10/main.go
+
+O/P :::::::::::::::::::
+
+6
+6
+true
+false
+
+[]
+[]
+PS 
+*/