小编Lis*_*ish的帖子

我已经在这几个小时,尝试不同的方法看几乎每个问题.也许我完全错了,但我觉得我的数学是正确的,但无论我输入什么数字,我都得到相同的输出.我的代码在某个地方关闭,我必须在午夜之前将其打开.

这一切都很有趣:找出一个点是否在三角形代码中.(对于初学者)

import java.util.Scanner;

public class PointsTriangle {

    // checks if point entered is within the triangle
    //given points of triangle are (0,0) (0,100) (200,0)
    public static void main (String [] args) {
        //obtain point (x,y) from user
        System.out.print("Enter a point's x- and y-coordinates: ");
        Scanner input = new Scanner(System.in);
        double x = input.nextDouble();
        double y = input.nextDouble();

        //find area of triangle with given points
        double ABC = ((0*(100-0  )+0*(0  -0)+200*(0-100))/2.0);
        double PAB = ((x*(0  -100)+0*(100-y)+0  *(y-  0))/2.0);
        double PBC …

我已经找了40多分钟试图在这个网站上找到可能与我的问题有关的答案无济于事.

我很难过.我正在尝试将程序转换为GUI.我正在使用Textpad,它在编译时告诉我变量已在main方法中定义.然后当转换为int或double时,它告诉我它找不到符号并指向我想要转换的变量.然后在我的计算过程中,它告诉我二进制运算符'*'的错误操作数类型.

import javax.swing.JOptionPane;

public class PayrollGUI {

// calculates payroll
public static void main (String [] args) {

String name = JOptionPane.showInputDialog ("Employee's Name: ");
int name = Integer.parseInt(nameString);

String hours = JOptionPane.showInputDialog ("Number of hours worked in a week (e.g., 10: ");
int hours = Integer.parseInt(hoursString);

String payRate = JOptionPane.showInputDialog ("Hourly pay rate (e.g., .6.75: ");
double payRate = Double.parseDouble(payRateString);

String federalTaxRate = JOptionPane.showInputDialog ("Federal tax witholding rate (e.g., .20: ");
double federalTaxRate = Double.parseDouble(federalTaxRateString);

String stateTaxRate = …