How do you convert a string to an integer in Go?

General Discussions
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1

In Go, the idiomatic way to convert a string to an integer is by using strconv.Atoi() or strconv.ParseInt().

If you’re working with command-line arguments like flag.Arg(n), you can convert it like this:

import (
    "fmt"
    "strconv"
)

str := "42"
num, err := strconv.Atoi(str)
if err != nil {
    // handle error
}
fmt.Println(num)

This is the recommended approach for golang string to int conversion.

2

I usually use strconv.Atoi() when converting strings to integers in Go especially when grabbing CLI args with flag.Arg(n).

num, err := strconv.Atoi(str)

Just don’t forget the error check, Go won’t let you skip it, and honestly, it’s saved me more than once from crashing apps.

3

In Go, I prefer strconv.ParseInt() if I need a bit more control, like specifying the base or bit size. It’s slightly more flexible than Atoi():

num, err := strconv.ParseInt("42", 10, 64)

This comes in handy when you’re parsing non-decimal strings or targeting specific int types.

4

I ran into this when parsing config values from a file. At first, I used fmt.Sscanf, but quickly switched to strconv.Atoi(), way more reliable and idiomatic in Go.

If you’re dealing with flags or user input, Atoi() is your friend. Just make sure to handle the error properly!