Go by Example: Number Parsing

Parsing numbers from strings is a basic but common task in many programs; here’s how to do it in Go.
	package main
The built-in package `strconv` provides the number parsing.	import "strconv" import "fmt"
	func main() {
With `ParseFloat`, this `64` tells how many bits of precision to parse.	f, _ := strconv.ParseFloat("1.234", 64) fmt.Println(f)
For `ParseInt`, the `0` means infer the base from the string. `64` requires that the result fit in 64 bits.	i, _ := strconv.ParseInt("123", 0, 64) fmt.Println(i)
`ParseInt` will recognize hex-formatted numbers.	d, _ := strconv.ParseInt("0x1c8", 0, 64) fmt.Println(d)
A `ParseUint` is also available.	u, _ := strconv.ParseUint("789", 0, 64) fmt.Println(u)
`Atoi` is a convenience function for basic base-10 `int` parsing.	k, _ := strconv.Atoi("135") fmt.Println(k)
Parse functions return an error on bad input.	_, e := strconv.Atoi("wat") fmt.Println(e) }

	$ go run number-parsing.go 1.234 123 456 789 135 strconv.ParseInt: parsing "wat": invalid syntax
Next we’ll look at another common parsing task: URLs.

Previous example: Random Numbers.

Next example: URL Parsing.