Make Your Zero Value Useful in Golang

Photo by Jeremy Perkins on Unsplash

In Go, when memory is allocated to store a value of a type, it is given a default value of that type. Why? Because the zero value makes your code more compact and more straightforward.

Let's look at the zero value of a few types and see how they are useful.

Zero Value

Zero values for all the types are as follows:

• Boolean: false
• Integer : 0
• Floating : 0.0
• String:""
• Interfaces, slices, channels, maps, pointers, and functions: nil

The elements of an array or struct will have their fields zeroed if no value is specified.

type Bar struct {
    n int
    f float64
    next *Bar
}
fmt.Println([2]Bar{})       // [{0 0 <nil>} {0 0 <nil>}

Let's see examples to show how these zero values can significantly simplify the API.

Example 1: Slice

The zero value of a slice is nil, so we can use it to check if a slice is empty or not.

var s []int
if s == nil {
  fmt.Println("slice is empty")
}

It's interesting to note that:

• A slice value with zero length is not the same as a nil…