基本的 Java 所得税
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Basic Java Income Tax
提问by Michael
The Question:
问题：
Write a program that prompts the user to enter his/her taxable income and then calculates the income tax due using the 2014 tax table below. Express the tax with two decimal places.
编写一个程序，提示用户输入他/她的应税收入，然后使用下面的 2014 年税表计算应缴所得税。用两位小数表示税额。
Income tax brackets for single-filers
up to 75 10%
76 - 900 15%
901 - 350 25%
351 - 6350 28%
6351 - 5100 33%
This is what I have so far. I'm really new to Java so keep that in mind. My specific question will come after my code.
这就是我迄今为止所拥有的。我对 Java 真的很陌生，所以请记住这一点。我的具体问题将在我的代码之后出现。
import java.util.Scanner;
public class IncomeTax {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
// Prompt the user to enter taxable income
System.out.print("Enter the amount of taxable income for the year 2014: ");
double income = input.nextDouble();
// Compute tax
double tax = 0;
if (income <= 9075)
tax = income * 0.10;
else if (income <= 9076)
tax = 9075 * 0.10 + (income - 36900) * 0.15;
else if (income <= 36901)
tax = 9075 * 0.10 + (9076 - 36900) * 0.15 + (income - 89350) * 0.25;
else if (income <= 89351)
tax = 9075 * 0.10 + (9076 - 36900) * 0.15 + (36901 - 89350) * 0.25 + (income - 186350) + 0.28;
else if (income <= 186351)
tax = 9075 * 0.10 + (9076 - 36900) * 0.15 + (36901 - 89350) * 0.25 + (89351 - 186350) + 0.28 + (income - 405100) + 0.33;
if (income <= 9075)
System.out.println("You have entered the 10% bracket.");
else if (income <= 9076)
System.out.println("You have entered the 15% bracket.");
else if (income <= 36901)
System.out.println("You have entered the 25% bracket.");
else if (income <= 89351)
System.out.println("You have entered the 28% bracket.");
else if (income <= 186351)
System.out.println("You have entered the 33% bracket.");
}
}
The final output should look like this:
最终输出应如下所示：
Enter the amount of taxable income for the year 2014. (user input here ->) 5000
输入2014年的应纳税所得额。（用户在此输入->）5000
You have entered the 10% tax bracket.
您已输入 10% 的税级。
Your income is $5,000.00, Your tax is: $500.00. Your income after tax is: $4,500.00
您的收入为 5,000.00 美元，您的税为：500.00 美元。您的税后收入为：$4,500.00
How do I get my output to look like the above output? Specifically the decimals and the $ sign.
如何让我的输出看起来像上面的输出？特别是小数点和 $ 符号。
The output code that I am currently working on is:
我目前正在处理的输出代码是：
System.out.println("Your income is: " + "Your taxx is: " + (int)(tax * 100) / 100.0) + "Your income after tax is: " + ;
回答by Willem Van Onsem
Simply append the following part to the code:
只需将以下部分附加到代码中：
DecimalFormat formatter = new DecimalFormat("###,###,###.00");
System.out.println("Your inccome is $"+formatter.format(income)+", your tax is: $"+formatter.format(tax)+". Your income after tax is: $"+formatter.format(income-tax));
Here the DecimalFormatteris a technique to format numbers properly (for instance with commas separating the thousands, and two digits after the decimal dot).
这DecimalFormatter是一种正确格式化数字的技术（例如用逗号分隔千位和小数点后的两位数）。
But your code is quite sloppy and error-prone and sometimes doesn't seem to make much sense. You can better subdivide the calculation of taxes using different brackets:
但是您的代码非常草率且容易出错，有时似乎没有多大意义。您可以使用不同的括号更好地细分税收的计算：
double[] max = {0,9075,36900,89350,186350,405100};
double[] rate = {0,0.10,0.15,0.25,0.28,0.33};
double left = income;
double tax = 0.0d;
for(int i = 1; i < max.length && left > 0; i++) {
double df = Math.min(max[i]-max[i-1],left);
tax += rate[i]*df;
left -= df;
}
回答by KSFT
All you need to do is print the tax. You can format it with NumberFormat, as mentioned here:
您需要做的就是打印税款。你可以用格式化NumberFormat，提到这里：
NumberFormat format = NumberFormat.getCurrencyInstance();
System.out.println("You have entered the 10% bracket.");
System.out.println("Your income is $"+format.format(income)+". Your tax is $"+tax+". Your income after tax is "+format.format(income-tax)+".");
回答by Abdelrahman Elkady
simplest way to use DecimalFormat
使用DecimalFormat 的最简单方法
you will need to import java.text.DecimalFormat
你需要导入 java.text.DecimalFormat
DecimalFormat formatter = new DecimalFormat("#,###.00");
System.out.println(formatter.format(1122334455));
will output :
将输出：
1,122,334,455.00
1,122,334,455.00
