java - 从方法返回数组

Question

这是在主课

actionsClass actionObject = new actionsClass(tipArray, hourArray, 
     hourlyWageInput, gasArray, wageArray, incomeArray, totalHourlyEarnings, 
     totalGas, totalHours, avgGasLabel);

actionObject.calculateTable();

这是我尝试实现该方法的类（当前声明的变量过多）：

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JTextField;

public class actionsClass {

private JLabel hourlyWage, blank, row2, totalTips, totalHours, totalHourlyEarnings, 
totalPay, weekPay, day, totalGas, totalHoursLabel, totalTipsLabel, totalGasLabel, 
totalWageLabel, avgGas, avgGasLabel;
private JTextField hourlyWageInput;

private double incomeArray[] = new double[7];
private JTextField tipArray[] = new JTextField[7];
private JTextField hourArray[] = new JTextField[7];
private JTextField gasArray[]= new JTextField[7];
private JLabel wageArray[] =new JLabel[7];


public actionsClass() {
}

public actionsClass(JTextField[] tipArray, JTextField[] hourArray,
        JTextField hourlyWageInput, JTextField[] gasArray,
        JLabel[] wageArray, double[] incomeArray,
        JLabel totalHourlyEarnings, JLabel totalGas, JLabel totalHours,
        JLabel avgGasLabel) {
    this.tipArray = tipArray;
    this.hourArray = hourArray;
    this.hourlyWageInput = hourlyWageInput;
    this.gasArray = gasArray;
    this.wageArray =  wageArray;
    this.incomeArray =  incomeArray;
    this.totalHourlyEarnings =  totalHourlyEarnings;
    this.totalGas = totalGas;
    this.totalHours = totalHours;
    this.avgGasLabel = avgGasLabel;
}

public String calculateTable (){
    for (int i = 0; i < 7; i++) {
        double tipx = Double.parseDouble(tipArray[i].getText());
        double houry = Double.parseDouble(hourArray[i].getText());
        double hourlyz = Double.parseDouble(hourlyWageInput.getText());

        String[] wageArrayStrings = null;

        if (houry != 0 ){
            wageArrayStrings[i] = String.format("%.2f", (hourlyz*houry+tipx)/houry);

        }
        else {
            wageArrayStrings[i] = ("$ 0.00");
        }

    }
    return wageArrayStrings[];
}

}

return wageArrayStrings[] 存在语法错误；带或不带括号。我究竟做错了什么？

Answer 1

首先，返回类型应该是String[].

然后你需要初始化数组（正如@MattBall 指出的，在循环之前）：

String[] wageArrayStrings = new String[7];
for (int i = 0; i < 7; i++) {

然后你可以做

return wageArrayStrings;

Answer 2

它应该只是 return wageArrayStrings; 不需要方括号，应该String[]改为返回类型String（假设您的意图是返回字符串数组）。

Answer 3

它应该只是（也改变了函数返回类型） -

public String[] calculateTable () {

    //// your code.
    return wageArrayStrings;
}

此外，您还没有初始化您的数组。您应该在 for 循环之前执行此操作。