How to Convert Float to String

Question

I read a float from a file and will have to convert it to string. My problem here is that I am unsure of how many digits will be there after the decimal. I need to take the float exactly and convert it to string.

For ex: 
1.10 should be converted to "1.10"
Also,
1.5 should be converted to "1.5"
Can someone suggest how to go about this?

Accepted Answer

Use strconv.FormatFloat like such:

s := strconv.FormatFloat(3.1415, 'f', -1, 64)
fmt.Println(s)

Outputs

3.1415

Answer 2

Must Read

Convert float to string

FormatFloat converts the floating-point number f to a string, according to the format fmt and precision prec. It rounds the result assuming that the original was obtained from a floating-point value of bitSize bits (32 for float32, 64 for float64).

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

f := 3.14159265
s := strconv.FormatFloat(f, 'E', -1, 64)
fmt.Println(s)

Output is "3.14159265"

Another method is by using fmt.Sprintf

s := fmt.Sprintf("%f", 123.456) 
fmt.Println(s)

Output is "123.456000"

Check the code on play ground

Answer 3

func main() {
    var x float32
    var y string
    x= 10.5
    y = fmt.Sprint(x)
    fmt.Println(y)
}

Answer 4

Depending on the size of your float number choose most suitable option:

var (
    floatNumber float64 = 27.156633168032640
)

fmt.Println("as float32 with 'E' (decimal exponent) :", strconv.FormatFloat(floatNumber, 'E', -1, 32))
fmt.Println("as float64 with 'E' (decimal exponent) :", strconv.FormatFloat(floatNumber, 'E', -1, 64))
fmt.Println("as float32 with 'f' (no exponent) :", strconv.FormatFloat(floatNumber, 'f', -1, 32))
fmt.Println("as float64 with 'f' (no exponent) :", strconv.FormatFloat(floatNumber, 'f', -1, 64))
fmt.Println("with fmt.Sprint :", fmt.Sprint(floatNumber))
fmt.Println("with fmt.Sprintf :", fmt.Sprintf("%f", floatNumber))

The result is:

P.S. for better performance you should use strconv.FormatFloat()

How to Convert Float to String

4 Answers

Must Read

Convert float to string

Elena Rostova