Question

我是Java和Android Studio的初学者。我做了一个（有点复杂）的计算器，可以计算分数，整数以及混合分数。它的工作原理是先将输入的数字（无论采用哪种格式）转换为分数，然后进行计算。这是代码的一部分：

buttonAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String fraction_1 = editTextNum1.getText().toString();
                String fraction_2 = editTextNum2.getText().toString();
                int Num1, Den1, Num2, Den2;
                if (fraction_1.contains("/") && !fraction_1.contains(" ")){
                    Num1 = Integer.parseInt(getFraction(fraction_1)[0]);
                    Den1 = Integer.parseInt(getFraction(fraction_1)[1]);
                } else if (fraction_1.contains(" ") && fraction_1.contains("/")){
                    int[] frac1 = convertFromMixed(fraction_1);
                    Num1 = frac1[0];
                    Den1 = frac1[1];
                }
                else if (!fraction_1.contains("/")) {
                    Num1 = Integer.parseInt(fraction_1);
                    Den1 = 1;
                }
                else{
                    invalidinput invalidinput = new invalidinput();
                    invalidinput.show(getSupportFragmentManager(), "num1error");

                }
                if (fraction_2.contains("/") && !fraction_2.contains(" ")){
                    Num2 = Integer.parseInt(getFraction(fraction_2)[0]);
                    Den2 = Integer.parseInt(getFraction(fraction_2)[1]);
                } else if (fraction_2.contains(" ") && fraction_2.contains("/")){
                    int[] frac2 = convertFromMixed(fraction_1);
                    Num2 = frac2[0];
                    Den2 = frac2[1];
                }
                else if (!fraction_2.contains("/")){
                    Num2 = Integer.parseInt(fraction_2);
                    Den2 = 1;
                } else{
                    invalidinput invalidinput = new invalidinput();
                    invalidinput.show(getSupportFragmentManager(), "num2error");

                }

                int commonDen = getLCM(Den1, Den2);
                Num1 = (commonDen/Den1)*Num1;
                Num2 = (commonDen/Den2)*Num2;
                int addNum = Num1 + Num2;

                if (simplify.isChecked()){
                    String result = simplify(addNum, commonDen);
                    result = checkFor1(result);
                    result = checkForWhole(result);


                    textViewResult.setText(result);
                } else {
                    String result = addNum + "/" + commonDen;
                    result = checkFor1(result);
                    textViewResult.setText(result);
                }
            }
        });

在最后一部分，计算commonDen时出现错误。它表示尚未初始化Num1，Num2，Den1和Den2。这只是附加部分。这些变量用于计算时，都会出现错误。请帮忙。

Answer 1

因此您必须初始化变量。您可以通过

改变

int Num1, Den1, Num2, Den2;

到

int Num1 = 0, Den1 = 0, Num2 = 0, Den2 = 0;

编译器说变量尚未初始化

1 个答案: