点击运行
package main import ( "errors" "fmt" "math" ) func circleArea(radius float64) (float64, error) { if radius < 0 { return 0, errors.New("面积计算失败，半径小于0。") } return math.Pi * radius * radius, nil } func main() { radius := -20.0 area, err := circleArea(radius) if err != nil { fmt.Println(err) return } fmt.Printf("圆的面积 %0.2f", area) }
运行结果 :
正在执行...
