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All variables have a zero value and are pre-initialized to their zero value. For example, an int would have a zero value of 0 and a string would have a zero value of empty string "".

Initializing the variable at declaration time:

var x int = 5

Example:

package main
  
import (
  "fmt"
)

func main(){
  var x int
  x = 5
  fmt.Println(x)
}

References

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