Go Short Variable

identifier := expression
identifier1, identifier2 := expression1, expression2

package main

import (
	"fmt"
	"os"
)

func main() {
	// Type inferred as int (default for untyped integer constant)
	count := 10 

	// Type inferred as float64 (default for untyped float constant)
	pi := 3.14  

	// Type inferred as bool (default for untyped boolean constant)
	isActive := true

	// Type explicitly derived from the RHS function return types
	file, err := os.Open("data.txt") 

	// Variables evaluated to satisfy the compiler's unused variable constraint
	fmt.Println(count, pi, isActive, file, err)
}

package main

import "fmt"

func main() {
	// 'a' and 'b' are newly declared
	a, b := 1, 2 

	// Valid: 'c' is new. 'a' is merely reassigned.
	a, c := 3, 4 

	// Invalid: The blank identifier (_) does not count as a new variable.
	// a, _ := 5, 6 // Compile error: no new variables on left side of :=

	// Variables evaluated to satisfy the compiler's unused variable constraint
	fmt.Println(a, b, c)
}

package main

import "fmt"

func main() {
	x := 10 // Outer scope 'x'

	if true {
		x := 5 // Declares a NEW 'x' in the inner scope, shadowing the outer 'x'
		x++    // Modifies the inner 'x' (becomes 6)
		
		fmt.Println(x) // Prints 6
	}

	// Outer 'x' remains 10
	fmt.Println(x) // Prints 10
}