Basics of Go language.

example.go

package main

import "fmt"

func main() {
	fmt.Println("Hello, world!")

	// Creating variables

	var x1 int = 5
	var y1 int = 10
	var sum1 int = x1 + y1
	fmt.Println(sum1)

	// Shorthand for creating variables

	x2 := 5
	y2 := 10
	sum2 := x2 + y2
	fmt.Println(sum2)

	// If-else statements

	number := 9
	if number < 10 {
		fmt.Println("The number is less than 10")
	} else if number == 10 {
		fmt.Println("The number is 10")
	} else {
		fmt.Println("The number is greater than 10")
	}
	
	// ARRAYS
	
	
	// Initialize an array with three zeros
	var arr1 [3]int
	fmt.Println(arr1) // prints [0 0 0]
	
	// Use an index to change elements in an array
	arr1[0] = 10
	fmt.Println(arr1) // prints [10 0 0]
	
	//A Shorthand for creating arrays
	arr2 := [3]int{1,2,3}
	fmt.Println(arr2) // prints [1 2 3]
	
	// These arrays are fixed in length. Pretty inconvenient
	// Let's create an array slice in which you can add elements
	
	arr3 := []int{1,2,3}
	arr3 = append(arr3, 4)
	fmt.Println(arr3) // prints [1 2 3 4]
	
	
	// DICTIONARIES A.K.A MAPS
	
	sides := make(map[string]int) // creates a string: int map
	
	// Adding new key-value pairs to the map
	sides["triangle"] = 3
	sides["square"] = 4
	sides["pentagon"] = 5
	
	fmt.Println(sides) // prints map[pentagon:5 square:4 triangle:3]
	
	delete(sides, "triangle")
	
	fmt.Println(sides) // prints map[pentagon:5 square:4]
	
	// LOOPS
	
	// In Go, there are only for loops
	
	// Loop numbers from 0 to 4 and print them
	for i := 0; i < 5; i++ {
		fmt.Println(i)
	}
	
	// For loop can be used as a while loop too
	i := 0
	
	for i < 5 {
		fmt.Println(i)
		i++
	}
	
	// Loop through an array using range
	numbers := []int{1,2,3}
	for index, value := range numbers {
		fmt.Println("Index:", index, "Value:", value)
	}
	
	// Loop through a map using range
	data := make(map[string]int) // creates a string: int map
	
	data["one"] = 1
	data["two"] = 2
	data["three"] = 3
	
	for key, value := range numbers {
		fmt.Println("Key:", key, "Value:", value)
	}
}