Java中的字段 toString() 方法及示例
Java.lang.reflect.Field的toString()方法用于获取描述该字段的字符串。返回字符串的格式是字段的访问修饰符(如果有),后跟字段类型,后跟空格,后跟声明该字段的类的完全限定名称,然后是句点,然后是字段的名称。
例如:
public static final Month java.time.Month.APRIL
修饰符按“ Java语言规范”指定的规范顺序放置。这是公共的、受保护的或私有的,然后是其他修饰符,顺序如下:静态、最终、瞬态、易失。
句法:
public String toString()
参数:此方法不接受任何内容。
返回值:该方法返回一个描述该字段的字符串。
下面的程序说明了 toString() 方法:
方案一:
// Java program to illustrate toString() method
import java.lang.reflect.Field;
public class GFG {
public static void main(String[] args)
throws Exception
{
// Get the array of field object
Field[] fields = User.class.getFields();
// loop
for (int i = 0; i < fields.length; i++) {
// get the string representation of each field
String field = fields[i].toString();
System.out.println("Field: " + field);
}
}
}
// sample User class
class User {
// static double values
public static double Marks = 34.13;
public static float Fees = 3413.99f;
public static String name = "Aman";
public static double getMarks()
{
return Marks;
}
public static void setMarks(double marks)
{
Marks = marks;
}
public static float getFees()
{
return Fees;
}
public static void setFees(float fees)
{
Fees = fees;
}
public static String getName()
{
return name;
}
public static void setName(String name)
{
User.name = name;
}
}
Field: public static double User.Marks
Field: public static float User.Fees
Field: public static java.lang.String User.name
方案二:
// Java program to illustrate toString() method
import java.lang.reflect.Field;
import java.time.Month;
public class GFG {
public static void main(String[] args)
throws Exception
{
// Get all field objects of Month class
Field[] fields = Month.class.getFields();
for (int i = 0; i < fields.length; i++) {
// print name of Fields
System.out.println("toString of Field:\n"
+ fields[i].toString());
}
}
}
toString of Field:
public static final java.time.Month java.time.Month.JANUARY
toString of Field:
public static final java.time.Month java.time.Month.FEBRUARY
toString of Field:
public static final java.time.Month java.time.Month.MARCH
toString of Field:
public static final java.time.Month java.time.Month.APRIL
toString of Field:
public static final java.time.Month java.time.Month.MAY
toString of Field:
public static final java.time.Month java.time.Month.JUNE
toString of Field:
public static final java.time.Month java.time.Month.JULY
toString of Field:
public static final java.time.Month java.time.Month.AUGUST
toString of Field:
public static final java.time.Month java.time.Month.SEPTEMBER
toString of Field:
public static final java.time.Month java.time.Month.OCTOBER
toString of Field:
public static final java.time.Month java.time.Month.NOVEMBER
toString of Field:
public static final java.time.Month java.time.Month.DECEMBER
参考: https: Java/lang/reflect/Field.html#toString–