amreshpro / go

Go Notes

• Staically typed
• Fast run time
• Compiled
• Fast Compiled time
• Supports concurrency through goroutines and channel.
• Has automatic garbage collection
• Does not support classes and objects
• Does not supports inheritance

first.go

package main
import "fmt"
func main()  {
  fmt.Println("Hello Golang")
}

fmt.Println("Hello World!") is a statement.

In Go, statements are separated by ending a line (hitting the Enter key) or by a semicolon ";".

Hitting the Enter key adds ";" to the end of the line implicitly (does not show up in the source code).

The left curly bracket { cannot come at the start of a line.

package main
import ("fmt")

func main()//error
{
  fmt.Println("Hello World!")
}

way1 - syntax :- var variablename type = value

way2 - with the := sign , variablename := value

Note: In this case, the type of the variable is inferred from the value (means that the compiler decides the type of the variable, based on the value).

Note: It is not possible to declare a variable using :=, without assigning a value to it.

var vs :=

var --> used inside or outside of function

:= --> only inside functions

var --> variable declaration and value assignment can done separately.

:= --> Variable declaration and value assignment cannot be done separately (must be done in the same line)

Note: If you use the type keyword, it is only possible to declare one type of variable per line.

If the type keyword is not specified, you can declare different types of variables in the same line:

 var a3, b3 = 6, "Hello"
	c3, d3 := 7, "World!"
	fmt.Println("-----")

	fmt.Println(a3)//6
	fmt.Println(b3)// "Hello"
	fmt.Println(c3)//7
	fmt.Println(d3)//World

Multiple variable declarations can also be grouped together into a block for greater readability:

func main() {
   var (
     a int
     b int = 1
     c string = "hello"
   )

  fmt.Println(a)
  fmt.Println(b)
  fmt.Println(c)
}

Multiple constants can be grouped together into a block for readability:

const (
  A int = 1
  B = 3.14
  C = "Hi!"
)