小编use*_*306的帖子

我正在尝试使用以下代码来计算用户输入的一组值的平均值,并将其显示在a中,jTextArea但它无法正常工作.比如,用户输入7,4和5,程序显示1作为应显示5.3的平均值

  ArrayList <Integer> marks = new ArrayList();
  Collections.addAll(marks, (Integer.parseInt(markInput.getText())));

  private void analyzeButtonActionPerformed(java.awt.event.ActionEvent evt) {
      analyzeTextArea.setText("Class average:" + calculateAverage(marks));
  }

  private int calculateAverage(List <Integer> marks) {
      int sum = 0;
      for (int i=0; i< marks.size(); i++) {
            sum += i;
      }
      return sum / marks.size();
  }

代码有什么问题？

码:

 ArrayList <Integer> marks = new ArrayList();

 String output = "Class average:" + calculateAverage() + "\n" + "Maximum mark:" +  
 calculateMaximum() + "\n" +"Minimum mark:" + calculateMinimum() + "\n" + "Range of 
 marks:" + range;

 analyzeTextArea.setText(output);

 private double calculateAverage(double [] marks) {
 double sum = 0;
 for (int i=0; i< marks.length; i++) {
 sum += marks[i];
 }
 return sum / marks.length;
 }

忽略字符串中的其他内容(最小值,最大值和范围)但对于此行,

 String output = "Class average:" + calculateAverage() + "\n" + "Maximum mark:" +  
 calculateMaximum() + "\n" +"Minimum …

码:

ArrayList <Integer> marks = new ArrayList();

private void addButtonActionPerformed(java.awt.event.ActionEvent evt) {
    Collections.addAll(marks, (Integer.parseInt(markInput.getText())));
    marks.add(Integer.parseInt(markInput.getText()));
    for (int j =0; j < marks.size(); j++) {
        markdisplayTextArea.setText(Integer.toString(marks.get(j)));
}

当用户输入JTextArea并按下"添加"按钮时,该程序应该在JTextArea的新行上显示每个数字.

它显示每个数字,但一次只显示一个.我希望输入的每个数字都以升序显示在新行上.因此,如果用户输入了4个数字,比如78,92,54和21,我希望它们显示如下:

21
54
78
92