Compute absolute value of an int/float

Integers

There is no built-in abs function for integers, but it’s simple to write your own.

// Abs returns the absolute value of x.
func Abs(x int64) int64 {
	if x < 0 {
		return -x
	}
	return x
}

Warning: The smallest value of a signed integer doesn’t have a matching positive value.

• math.MinInt64 is -9223372036854775808, but
• math.MaxInt64 is 9223372036854775807.

Unfortunately, our Abs function returns a negative value in this case.

fmt.Println(Abs(math.MinInt64))
// Output: -9223372036854775808

(The Java and C libraries behave like this as well.)

Floats

The math.Abs function returns the absolute value of x.

func Abs(x float64) float64

Special cases:

Abs(±Inf) = +Inf
Abs(NaN) = NaN

More code examples

Go blueprints: code for com­mon tasks is a collection of handy code examples.

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