How to Format Floating Point Numbers in Go: fmt.Sprintf() vs. strconv.FormatFloat()?

Formatting Floating Point Numbers in Go

In Go, there are several methods to convert a floating point number into a string. Two popular choices include fmt.Sprintf() and strconv.FormatFloat(). Each approach has its nuances, but they ultimately leverage the same underlying string formatting mechanisms.

Choosing the Appropriate Method

When deciding between fmt.Sprintf() and strconv.FormatFloat(), consider the following:

• Precision Flexibility: If the number of decimal places needs to vary dynamically, strconv.FormatFloat() is more convenient as it accepts a precision parameter that can be adjusted accordingly.

Usage and Differences

fmt.Sprintf()

Syntax:

func Sprintf(format string, a ...interface{}) string

Usage:

fResult := 123.456
sResult := fmt.Sprintf("%.2f", fResult) // Format the number to two decimal places

strconv.FormatFloat()

Syntax:

func FormatFloat(f float64, fmt byte, prec, bitSize int) string

Usage:

fResult := float64(123.456)
sResult := strconv.FormatFloat(fResult, 'f', 2, 32) // Format the number to two decimal places, assuming it's a float64

Significance of bitSize in strconv.FormatFloat()

The bitSize parameter in strconv.FormatFloat() controls how rounding is performed. It assumes that the original floating point value had the specified bit size (32 for float32, 64 for float64). By specifying the correct bitSize, the rounding behavior is optimized for the actual data type of the input.

The above is the detailed content of How to Format Floating Point Numbers in Go: fmt.Sprintf() vs. strconv.FormatFloat()?. For more information, please follow other related articles on the PHP Chinese website!