How to solve the problem with float for monetary operations?

The problem with using float for monetary operations is related to loss of precision due to the characteristics of floating-point representation.

To avoid errors when working with money, the following approaches are usually used:

• Use integer types to store amounts in minimal units (for example, kopecks or cents). For example, instead of 10.50, store 1050.
• Use specialized libraries for decimal arithmetic (decimal), which provide accurate calculations without rounding errors.

In Go, you can use the math/big package with the big.Rat type or third-party libraries for decimal arithmetic.

Example using the integer approach:

package main
import "fmt"

func main() {
    var priceInCents int64 = 1050 // 10.50 rubles
    var quantity int64 = 3
    total := priceInCents * quantity
    fmt.Printf("Total: %d kopecks\n", total) // 3150 kopecks = 31.50 rubles
}