Go Float Data Type

Float data types in Go are designed for storing both positive and negative numbers that include a decimal point. These can represent numbers such as 12.75, -3.14, or 98765.4321.

In Go, float comes in two variations:

Tip: If a specific float type is not defined, the default type in Go will be float64.

The float32 Keyword

The float32 type is capable of storing numbers within a more restricted range compared to float64.

Example: Declaring Variables of Type float32

package main
import ("fmt")

func main() {
  var ducati float32 = 150.45
  var yamaha float32 = 3.4e+38
  fmt.Printf("Type: %T, value: %v\n", ducati, ducati)
  fmt.Printf("Type: %T, value: %v", yamaha, yamaha)
}

package main

import ("fmt")

​

func main() {

  var ducati float32 = 150.45

  var yamaha float32 = 3.4e+38

  fmt.Printf("Type: %T, value: %v\n", ducati, ducati)

  fmt.Printf("Type: %T, value: %v", yamaha, yamaha)

}

The float64 Keyword

The float64 type is capable of storing significantly larger numbers compared to float32.

Example: Declaring Variables of Type float64

package main
import ("fmt")

func main() {
  var suzuki float64 = 1.7e+308
  fmt.Printf("Type: %T, value: %v", suzuki, suzuki)
}

package main

import ("fmt")

​

func main() {

  var suzuki float64 = 1.7e+308

  fmt.Printf("Type: %T, value: %v", suzuki, suzuki)

}

Choosing Between Float Types

Selecting the appropriate float type depends on the range and precision of the value that needs to be stored.

Example: Out-of-Range Error for float32

package main
import ("fmt")

func main() {
  var honda float32 = 3.4e+39
  fmt.Println(honda)
}

package main

import ("fmt")

​

func main() {

  var honda float32 = 3.4e+39

  fmt.Println(honda)

}

Output:

./prog.go:5:7: constant 3.4e+39 overflows float32

./prog.go:5:7: constant 3.4e+39 overflows float32