Golang: if then else

By Xah Lee. Date: . Last updated: .

If

package main

import "fmt"

func main() {

    var x = 3

    if x < 0 {
        fmt.Println("no")
    }

    fmt.Println("yes")

}

Note, there's no parenthesis after the “if”.

If else

package main

import "fmt"

func main() {

    var x = 3

    if x < 0 {
        fmt.Printf("no")
    } else {
        fmt.Printf("yes")
    }

}

else if

package main

import "fmt"

func main() {

    var x = 3

    if x < 0 {
        fmt.Println(-1)
    } else if x > 0 {
        fmt.Println(1)
    } else {
        fmt.Println(0)
    }

}

If with a short statement

The if statement can start with a short statement to execute before the condition.

Variables declared by the statement are in scope of the if block and all the else blocks.

package main

import "fmt"

func main() {

    var x = 3

    // if statement can start with a short statement
    if i := -2; x < i {
        fmt.Println("no")
    }

    fmt.Println("yes")

}

ternary if, if expression

There's no “if expression”, such as JavaScript's ( test ? expr1 : expr2 )

Reference

The Go Programming Language Specification - The Go Programming Language#If_statements

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Golang

  1. Compile, Run
  2. Source Encoding
  3. Package, Import
  4. Comment
  5. Print
  6. String
  7. String Backslash Escape
  8. Rune
  9. Variable
  10. Zero Value
  11. Constant
  12. If Then Else
  13. Switch/Case
  14. Loop
  15. Basic Types
  16. Array
  17. Slice
  18. Map
  19. Struct
  20. Function
  21. String as Chars
  22. regexp
  23. Read File
  24. Write to File
  25. Walk Dir
  26. Check File Exist
  27. System Call
  28. Get Script Path
  29. Pointer
  30. Defer
  31. Random Number

Examples

  1. match any regexp
  2. Validate Links
  3. Generate Sitemap

Reference

  1. Go Spec