update

golang-learn/base/52-error_handling1/main.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"math"
+)
+
+type DivideError struct {
+	Dividend int
+	Divisor  int
+}
+
+func MySqrt(f float64) (float64, error) {
+	if f < 0 {
+		return 0, errors.New("math: square root of negative number")
+	}
+	return math.Sqrt(f), nil
+}
+
+func divide(a, b int) (int, error) {
+	if b == 0 {
+		return 0, errors.New("division by zero")
+	}
+	return a / b, nil
+}
+
+func (e *DivideError) Error() string {
+	return fmt.Sprintf("cannot divide %d by %d", e.Dividend, e.Divisor)
+}
+
+func custom_divide(a, b int) (int, error) {
+	if b == 0 {
+		return 0, &DivideError{Dividend: a, Divisor: b}
+	}
+	return a / b, nil
+}
+
+func main() {
+	// errors 接口
+	err := errors.New("this is an error")
+	fmt.Println(err)
+
+	x := 16.0
+	sqrt, err := MySqrt(x)
+	if err != nil {
+		fmt.Println("error:", err)
+		return
+	}
+	fmt.Println("sqrt:", sqrt)
+
+	// 显示返回错误
+	result, err := divide(10, 0)
+	if err != nil {
+		fmt.Println("Error: ", err)
+	} else {
+		fmt.Println("Result: ", result)
+	}
+
+	// 自定义错误
+	_, err = custom_divide(10, 0)
+	if err != nil {
+		fmt.Println(err)
+	}
+}