Is it required to assign default value to variable?

Question

In Go, when a variable is declared it is initialized with zero value as described in the specification.

http://golang.org/ref/spec#The_zero_value

But is it good coding practice to make use of this property and do not explicitly initialize your variable if it needs to initialized with the default value.

for example in the following example

http://play.golang.org/p/Mvh_zwFkOu

package main

import "fmt"

type B struct {
    isInit bool
    Greeting string
}

func (b *B) Init() {
    b.isInit = true
    b.Greeting = "Thak you for your time"
}

func (b *B) IsInitialized() bool {
    return b.isInit
}

func main() {
    var b B
    if !b.IsInitialized(){
        b.Init()
    }
    fmt.Println(b.Greeting)
}

The program relies on the default value of boolean to be false.

Answer 1

When a variable is declared it contains automatically the default zero or null value for its type: 0 for int, 0.0 for float, false for bool, empty string for string, nil for pointer, zero-ed struct, etc.

All memory in Go is initialized!.

For example: var arr [5]int in memory can be visualized as:

+---+---+---+---+ | | | | | +---+---+---+---+ 0 1 2 3

When declaring an array, each item in it is automatically initialized with the default zero-value of the type, here all items default to 0.

So preferably it's better to initialize without default value, in other cases than the situations when you explicitly want to declare a variable with a default value.