fen and yuan

currency/amountConvert.go

@@ -4,6 +4,7 @@ import (
 	"strconv"
 
 	"github.com/shopspring/decimal"
+	"golang.org/x/exp/constraints"
 )
 
 // @title 分转换为元
@@ -19,7 +20,6 @@ func CentToDollar(cent int32) string {
 
 // 元转换为分
 func DollarToCent(dollar string) int64 {
-
 	p, _ := strconv.ParseFloat(dollar, 64)
 	d := decimal.New(1, 2)
 
@@ -27,3 +27,16 @@ func DollarToCent(dollar string) int64 {
 
 	return df
 }
+
+func FenToYuan[T constraints.Integer](v T) string {
+	d := decimal.New(1, 2)
+
+	return decimal.NewFromInt(int64(v)).DivRound(d, 2).StringFixedBank(2)
+}
+
+func YuanToFen(yuan string) int64 {
+	p, _ := decimal.NewFromString(yuan)
+
+	d := decimal.New(1, 2)
+	return p.Mul(d).IntPart()
+}

currency/amountConvert_test.go

@@ -45,3 +45,45 @@ func TestDollarToCent(t *testing.T) {
 		}
 	}
 }
+
+func TestYuanToFen(t *testing.T) {
+	cases := []struct {
+		dollar   string
+		excepted int64
+	}{
+		{"240.40", 24040},
+		{"999999.40", 99999940},
+		{"999.99", 99999},
+		{"0.01", 1},
+		{"999999.01", 99999901},
+		{"1000000.99", 100000099},
+	}
+
+	for _, c := range cases {
+		result := YuanToFen(c.dollar)
+		if result != c.excepted {
+			t.Fatalf("dollar to cent failed, dollar:%s execpted:%d result:%d", c.dollar, c.excepted, result)
+		}
+	}
+}
+
+func TestFenToYuan(t *testing.T) {
+	cases := []struct {
+		cent     int
+		excepted string
+	}{
+		{24040, "240.40"},
+		{99999940, "999999.40"},
+		{99999, "999.99"},
+		{1, "0.01"},
+		{99999901, "999999.01"},
+		{100000099, "1000000.99"},
+	}
+
+	for _, c := range cases {
+		result := FenToYuan(c.cent)
+		if result != c.excepted {
+			t.Fatalf("dollar to cent failed, dollar:%d execpted:%s result:%s", c.cent, c.excepted, result)
+		}
+	}
+}