I have 2 fields that I have to multiply. One is a *float32 field and another is an int field. How can I multiply these fields?
var totalPrice *float32
var price *float32
var volume int
this code doesn't work. I get the error ... mismatched types *float32 ...
totalPrice = price * volume
You need to convert using type conversion as is explained quickly here. In this case as mkopriva highlight in his comment, you should convert volume variable's value to a float32.
Also allow to show a way to deal with nil values that has a meaning in the application level, for that i wrote the float32PtrToFloat(*float32,float32) with the second parameter that allows you to specify what value shall be taken instead of nil.
Assuming that a nil value translates to zero value, here goes the complete example
package main
import (
"fmt"
)
func main() {
var totalPrice *float32
var price *float32
var volume int
var total = float32PtrToFloat(price, 0) * float32(volume)
totalPrice = &total
fmt.Println(*totalPrice)
}
func float32PtrToFloat(price *float32, valueIfNil float32) float32 {
if price == nil {
return valueIfNil
} else {
return *price
}
}
And a personal reading, following JimB advice, try to not use floats for currency values as floating point arithmetic is not reliable. Instead use integer values, using the 1 as the lower value in the current currency, for example: