Java 将字符串解析为数组?
我试图得到最多25个数字的平均值。现在,我对如何将Java 将字符串解析为数组?,java,arrays,parsing,Java,Arrays,Parsing,我试图得到最多25个数字的平均值。现在,我对如何将字符串解析为数组感到困惑。以下是目前的代码: 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 == (""))
字符串
解析为数组感到困惑。以下是目前的代码:
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 for(inti=0;i据我所知,您希望将多达25个双常量作为单个字符串读取,并将它们解析为双数组
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));
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(""));
您遇到了什么问题?我看到您有Double.parseDouble
,因此您确实有一些解析方面的知识。什么对您不起作用?我看不出您在哪里尝试将字符串添加到数组中。但在您的情况下,您不能;您的数组是一个双精度值数组,不能强制转换为双精度值。您最终尝试做什么?如果您想将字符串转换为求和,您已经用行Double.paraeDouble(s);
line完成了。当我输入该行时,编译器说我不能,因为它是Double[]不是双精度。您可能希望将while
条件更改为&
而不是|
为计数器引入一些变量,然后执行类似gradeArray[counter++]=grades
…顺便说一句的操作。您的代码质量确实很差(s==(“”
,s!=null | | s.equals(“
),等等)