switch.go

// basic example and concept buildig for switch expression
package main

import (
  "fmt"
)

func main()  {
  num := 3
  switch num {
  case 1:
    fmt.Println("num is one")
  case 2:
    fmt.Println("num is two")
  case 3, 4, 5:                  // here we can pass as many as we want values if they belong to same group
    fmt.Println("num is three")
  default:      // default case if no case will run it will fire
    fmt.Println("num is not 1 2 3 4 5")
  }

  // we can provide expression in the switch statement ot check

  switch i := 2 + 3; i {
  case 1:
    fmt.Println("num is one")
  case 2:
    fmt.Println("num is two")
  case 3, 4, 5:                  // here we can pass as many as we want values if they belong to same group
    fmt.Println("num is three")
  default:      // default case if no case will run it will fire
    fmt.Println("num is not 1 2 3 4 5")
  }

  // we can use it directly as if else if block without giving value at switch we can provide it at the place of Case

  switch { // here we can cover negative values as well
  case num <= 1:
    fmt.Println("num is less then or equal then one")
  case num <= 2:
    fmt.Println("num is less then or equal then two")
  default:      // default case if no case will run it will fire
    fmt.Println("num is more then two")
  }

  // fallthrough use
  // fallthrough will check for next condition as well to match other wise it will automatically break there

  switch { // here we can cover negative values as well
  case num <= 1:
    fmt.Println("num is less then or equal then one")
    fallthrough
  case num <= 2:
    fmt.Println("num is  less then or equal then two") // it will allow to print this as well
  default:      // default case if no case will run it will fire
    fmt.Println("num is more then two")
  }

}