Zero Value

By Xah Lee. Date: . Last updated: .

Variables declared without an explicit initial value are given their default value.

Default value are different for different types of variables.

The default value for a type is called its “zero value”.

The zero values are:

package main

import "fmt"

func main() {

	var i int
	var f float64
	var b bool
	var str string
	var sl []int

	fmt.Printf("%#v\n", i)   // 0
	fmt.Printf("%#v\n", f)   // 0
	fmt.Printf("%#v\n", b)   // false
	fmt.Printf("%#v\n", str) // ""
	fmt.Printf("%#v\n", sl)  // []int(nil)

	// %#v means print in golang syntax
}

Reference

The Go Programming Language Specification - The Go Programming Language#The_zero_value

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Golang

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

Examples

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  3. Validate Links
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Reference

  1. Go Spec