1

私は現在、基本的に同じように設定された一連のメソッドを持つプログラムを書いています。i = 1が与えられた場合、製品の価格に注文数量を掛けたものが返されます。それ以外の場合は、注文した数量を返すだけです。ただし、コンパイルしようとすると、コンパイラは角かっこにreturnステートメントがないことを通知します。私はコードを数回調べましたが、構文に明らかに間違っているものは何もありません。なぜこれが起こっているのかについての推測はありますか？

助けてくれてありがとう。

関連する情報源： 

private class ButtonListener implements ActionListener {
        public void actionPerformed(ActionEvent e)
        {
            if (e.getSource() == switchCard)
            {
                cl.show(infoPanel, (String)candyList.getSelectedValue());
            }

        if (e.getSource() == checkoutButton)
        {
            double acidPops = acidPopsTotal(1);
            double bertieBotts = bertieBottsTotal(1);
            double bloodPops = bloodPopsTotal(1);
            double cauldronCakes = cauldronCakesTotal(1);
            double charmChoc = charmChocTotal(1);
            double chocoballs = chocoballsTotal(1);
            double chocCauldrons = chocCauldronsTotal(1);
            double chocFrogs = chocFrogsTotal(1);
            double chocWands = chocWandsTotal(1);
            double roachClusters = roachClustersTotal(1);
            double crystalPineapple = crystalPineappleTotal(1);
            double droobleGum = droobleGumTotal(1);
            double explodeBonbons = explodeBonbonsTotal(1);
            double fizzWhiz = fizzWhizTotal(1);
            double iceMice = iceMiceTotal(1);
            double jellySlugs = jellySlugsTotal(1);
            double liquorWands = liquorWandsTotal(1);
            double pepImpts = pepImpsTotal(1);
            double pinkIce = pinkIceTotal(1);
            double shockChoc = shockChocTotal(1);
            double spindleSpiders = spindleSpidersTotal(1);
            double quills = quillsTotal(1);
            double wizochoc = wizochocTotal(1);
        }
    }

    double acidPopsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (5.95* (Integer.parseInt(acidPopsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(acidPopsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double bertieBottsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (16.95 * (Integer.parseInt(bertieBottsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(bertieBottsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double bloodPopsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (5.95 * (Integer.parseInt(bloodPopsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(bloodPopsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double cauldronCakesTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (14.95 * (Integer.parseInt(cauldronCakesTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(cauldronCakesTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double charmChocTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (5.95 * (Integer.parseInt(charmChocTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(charmChocTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double chocoballsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (9.95 * (Integer.parseInt(chocoballsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(chocoballsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double chocCauldronsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (14.95 * (Integer.parseInt(chocCauldronsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(chocCauldronsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double chocFrogsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (14.95 * (Integer.parseInt(chocFrogsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(chocFrogsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double chocWandsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (9.95 * (Integer.parseInt(chocWandsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(chocWandsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double roachClustersTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (5.95 * (Integer.parseInt(roachClustersTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(roachClustersTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double crystalPineappleTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (9.95 * (Integer.parseInt(crystalPineappleTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(crystalPineappleTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double droobleGumTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (2.95 * (Integer.parseInt(droobleGumTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(droobleGumTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double explodeBonbonsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (9.95 * (Integer.parseInt(explodeBonbonsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(explodeBonbonsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double fizzWhizTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (9.95 * (Integer.parseInt(fizzWhizTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(fizzWhizTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double iceMiceTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (5.95 * (Integer.parseInt(iceMiceTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(iceMiceTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double jellySlugsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (2.95 * (Integer.parseInt(jellySlugsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(jellySlugsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double liquorWandsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (9.95 * (Integer.parseInt(liquorWandsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(liquorWandsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double pepImpsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (4.95 * (Integer.parseInt(pepImpsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(pepImpsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double pinkIceTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (4.95 * (Integer.parseInt(pinkCocoIceTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(pinkCocoIceTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double shockChocTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (4.95 * (Integer.parseInt(shockChocTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(shockChocTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double spindleSpidersTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (4.95 * (Integer.parseInt(spindleSpidersTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(spindleSpidersTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double quillsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (1.95 * (Integer.parseInt(sugarQuillsTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(sugarQuillsTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }

    double wizochocTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (5.95 * (Integer.parseInt(wizochocTF.getText())));
            }
            catch (NumberFormatException e) {}
        }
        else
        {
            try
            {
                return Integer.parseInt(wizochocTF.getText());
            }
            catch (NumberFormatException e) {}
        }
    }
}

エラー：

C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:490: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:510: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:530: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:550: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:570: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:590: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:610: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:630: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:650: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:670: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:690: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:710: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:730: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:750: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:770: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:790: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:810: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:830: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:850: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:870: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:890: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:910: error: missing return statement
        }
        ^
C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java:930: error: missing return statement
        }
        ^
Note: C:\Users\Sam\Desktop\Java\4H 2012\ClientApp.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
23 errors
4

3 に答える 3

6

try-catchブロックのため、返品は保証されません。

これを示すために、0または-1の番兵を返すことをお勧めします。

これをより明確にする可能性のある例：

double acidPopsTotal(int i) {
    if (i == 1) {
        try {
            return (5.95* (Integer.parseInt(acidPopsTF.getText())));
        } catch (NumberFormatException e) {
            //Missing return - compile error
        }
    } else {
        try {
            return Integer.parseInt(acidPopsTF.getText());
        } catch (NumberFormatException e) {
            //Missing return - compile error
        }
    }
}
于 2012-07-10T23:45:55.543 に答える
1

Javaでは、returnまたはthrowを含まない非void関数を通るパスが少なくとも1つ存在する場合、コンパイル時エラーになります。スローされた例外をキャッチして何もしないため、そのパスには何も返されません。したがって、エラー。

余談ですが、例外を食べる代わりにスローするプログラム構造を検討することをお勧めします。（繰り返しになりますが、これはおそらく単なるサンプルコードです。）

于 2012-07-10T23:46:12.270 に答える
1

TheZの言ったことは正しいと思います。エラーが発生した場合、何も返さない可能性があります。次のようなものを試してください...

 double chocFrogsTotal(int i)
    {
        if (i == 1)
        {
            try
            {
                return (14.95 * (Integer.parseInt(chocFrogsTF.getText())));
            }
            catch (NumberFormatException e) {return -1.;}
        }
        else
        {
            try
            {
                return Integer.parseInt(chocFrogsTF.getText());
            }
            catch (NumberFormatException e) {return -1.;}
        }
    }

次に、1未満の値を返すときはいつでも、解析が不適切であることがわかります。

于 2012-07-10T23:50:06.933 に答える