Floating-point numbers

Go has floating point numbers corresponding to the IEEE 754 standard:

float32 is a 4 byte floating-point number (known as float in C)
float64 is a 8 byte floating-point number (known as double in C)

Zero value of float32 and float64 is 0.0.

Convert float to string with `FormatFloat`

main.go

	var f32 float32 = 1.3
	bitSize := 32
	s1 := strconv.FormatFloat(float64(f32), 'E', -1, bitSize)
	fmt.Printf("f32: %s\n", s1)

	var f64 float64 = 8.1234
	bitSize = 64
	s2 := strconv.FormatFloat(f64, 'e', -1, bitSize)
	fmt.Printf("f64: %s\n", s2)

Output:

f32: 1.3E+00
f64: 8.1234e+00

Convert float to string with `Sprintf`

main.go

	var f64 float64 = 1.54
	s := fmt.Sprintf("%f", f64)
	fmt.Printf("f is: '%s'\n", s)

Output:

f is: '1.540000'

Using strconv.FormatFloat is faster than fmt.Sprintf.

Convert string to float with `ParseFloat`

main.go

	s := "1.2341"
	f64, err := strconv.ParseFloat(s, 64)
	if err != nil {
		log.Fatalf("strconv.ParseFloat() failed with '%s'\n", err)
	}
	fmt.Printf("f64: %f\n", f64)

Output:

f64: 1.234100

Convert string to float with `Sscanf`

main.go

	s := "1.2341"
	var f float64
	_, err := fmt.Sscanf(s, "%f", &f)
	if err != nil {
		log.Fatalf("fmt.Sscanf failed with '%s'\n", err)
	}
	fmt.Printf("f: %f\n", f)

Output:

f: 1.234100

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Table Of Contents

Floating-point numbers

Convert float to string with FormatFloat

Convert float to string with Sprintf

Convert string to float with ParseFloat

Convert string to float with Sscanf

Convert float to string with `FormatFloat`

Convert float to string with `Sprintf`

Convert string to float with `ParseFloat`

Convert string to float with `Sscanf`