Question

我试图获得最多25个数字的平均值。现在，我对如何将String解析成数组感到困惑。这是代码：

final int SIZE = 25;
gradeArray = new double[SIZE];
String s;
int numElem = 0;
double average = 0;

do {
    s = (String) JOptionPane.showInputDialog("Enter Grade", "");
    if (s == null || s == ("")) {

    } else {
        try {
            grades = Double.parseDouble(s);
            if (grades > SIZE) 

        } catch (NumberFormatException e) {
            JOptionPane.showMessageDialog(null, "Your input must be numeric!",
                    "Bad             Data!", 0);
        }
    }
} while (s != null || !s.equals(""));

SIZE常量用于测试目的。

Answer 1

for(int i=0;i<SIZE;i++)
{
 s = (String)JOptionPane.showInputDialog("Enter Grade","");
    if(s != null && !(s.trim().equals(""))){
        gradeArray[i] = Double.parseDouble(s);
    }
    else{
        gradeArray[i] = 0;
    }

}

double sum=0;
for(int j=0;j<gradeArray.length;j++)
{
      sum+=gradeArray[j];
}


System.out.println("avaerage of grades ="+SIZE+" is ="+(sum/SIZE));

Answer 2

根据我的理解，你想要读取多达25个双常量作为单个字符串并将它们解析为双数组。

final int SIZE = 25;
gradeArray = new double[SIZE];
String s;
int numElem = 0;
double average = 0;

do {
s = (String) JOptionPane.showInputDialog("Enter Grade", "");
if (s == null || s == ("")) {

} else {
    try {
       // this will find double values in your string but ignores non double values
       Matcher m = Pattern.compile("(?!=\\d\\.\\d\\.)([\\d.]+)").matcher(s);
       int temp = 0;
       while (m.find())
       {
         gradeArray[temp] = Double.parseDouble(m.group(1));
         temp ++;
         if(temp >= SIZE){
             break;
         }
       }

    } catch (NumberFormatException e) {
        JOptionPane.showMessageDialog(null, "Your input must be numeric!",
                "Bad             Data!", 0);
    }
}
} while (s != null || !s.equals(""));

将字符串解析为数组？

2 个答案: