java - Java for 循环逻辑的问题

Question

我无法理解为什么我的 for 循环没有按我希望的那样运行。我循环的目的是将多个文本字段添加到 GUI 上，准确地说是 70 个。 7 个横向，10 个向下。它很好地添加了字段，但比我想要的短了一行和一列。这似乎足以确定问题的信息，但我不能，所以我来到了这里。

        for(int i = 0; i < 6; i++){
            for(int j = 0; j < 9; j++){
                OT2Field[i][j] = new JTextField();
                OT1Field[i][j] = new JTextField();
                STField[i][j] = new JTextField();
            }
        }

        int xPointer = 3;
        int yPointer = 7;
        for(int i = 0; i < 6; i++){
            for(int j = 0; j < 9; j++){
                addTimeFieldBorder0010(option3, OT2Field[i][j], gridbag, gbc, xPointer, yPointer, 1, 1, 0);
                yPointer = yPointer + 3;
            }
            xPointer++;
            yPointer = 7;
        }


    }

    private void addTimeFieldBorder0010(JComponent container, JComponent component, 
            GridBagLayout gridbag, GridBagConstraints gbc,
            int x, int y, int height, int width, double weightx) {
        gbc.gridx = x;
        gbc.gridy = y;
        gbc.gridheight = height;
        gbc.gridwidth = width;
        gbc.weightx = weightx;
        ((JTextField) component).setHorizontalAlignment(JLabel.CENTER);
        component.setBorder(BorderFactory.createMatteBorder(0, 0, 1, 0, Color.red));
        component.setFont(component.getFont().deriveFont(18.0f));
        component.setForeground(Color.red);
        component.setBackground(Color.YELLOW);
        gridbag.setConstraints(component, gbc);


        container.add(component, gbc);
     }

Answer 1

根据Java Language Specification §15.20.1 ,

• The value produced by the < operator is true if the value of the left-hand operand is less than the value of the right-hand operand, and otherwise is false.

所以您的起点是 i = 0并循环 i 小于 6。当它小于 7 或小于或等于 6 时，您需要循环。这同样适用于您的下一个循环。

将您的两个循环更改为:

for(int i = 0; i < 7; i++){
    for(int j = 0; j < 10; j++){
        //stuff
    }
}