使用 Java 枚举通过向量进行枚举
原文:https://www . geesforgeks . org/enumerate-through-a-vector-using-Java-enumeration/
在 Java Enumeration 类中，默认情况下，所有列出的常量都是公共的、静态的和最终的。现在在创建一个向量之后，如果我们想要枚举向量，那么首先，我们必须获得向量元素的枚举，为此，我们使用元素()方法。这个方法是Java . util . vector类的成员函数。 elements() 方法返回对实现 java.util.Enumeration 类的对象的引用，因此我们能够使用hasmorelements()和 nextElement() 方法来帮助我们通过 Vector 进行枚举。
申报
public Enumeration<Object> elements()
语法:
Enumeration enu = Vector.elements()
参数:该方法不取任何参数。
返回值:该方法返回向量值的 枚举 。
| 方法 | 返回 | | --- | --- | | **【hasmorellis()** | 如果枚举中存在更多元素，则返回真，否则返回假。 | | **nextElement()** | 如果枚举中存在下一个元素，则返回该元素。 |例 1:
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to Enumerate through a Vector
import java.util.Enumeration;
import java.util.Vector;
class GFG {
public static void main(String[] args) {
// Creating an object of Vector which contains
// String type elements
Vector<String> vector = new Vector<>();
// Adding values to the Vector
vector.add("Keep");
vector.add("Calm");
vector.add("and");
vector.add("learn");
vector.add("from");
vector.add("GFG");
// Displaying the values of the vector
System.out.println("The elements of the Vector is : "
+ vector);
// Creating the Enumeration of the Vector elements.
Enumeration enumeration = vector.elements();
// Now Enumerating through the Vector and
// printing each enumeration constant.
System.out.println(
"The output after Enumerating through the Vector : ");
while (enumeration.hasMoreElements()) {
System.out.println(enumeration.nextElement());
}
}
}
Output
The elements of the Vector is : [Keep, Calm, and, learn, from, GFG]
The output after Enumerating through the Vector :
Keep
Calm
and
learn
from
GFG
例 2:
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to Enumerate through a Vector
import java.util.Enumeration;
import java.util.Vector;
class GFG {
public static void main(String[] args) {
// Creating an object of Vector which contains
// double type elements
Vector<Double> vector = new Vector<>();
// Adding values to the Vector
vector.add(1.2636);
vector.add(23.0258);
vector.add(266.1125);
vector.add(2548.0125);
vector.add(2154.02415);
vector.add(856.012);
// Displaying the values of the vector
System.out.println("The elements of the Vector is : "
+ vector);
// Creating the Enumeration of the Vector elements.
Enumeration enumeration = vector.elements();
// Now Enumerating through the Vector and printing
// each enumeration constant.
System.out.println(
"The output after Enumerating through the Vector : ");
while (enumeration.hasMoreElements()) {
System.out.println(enumeration.nextElement());
}
}
}
Output
The elements of the Vector is : [1.2636, 23.0258, 266.1125, 2548.0125, 2154.02415, 856.012]
The output after Enumerating through the Vector :
1.2636
23.0258
266.1125
2548.0125
2154.02415
856.012
例 3:
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to Enumerate through a Vector
import java.util.Enumeration;
import java.util.Vector;
class GFG {
public static void main(String[] args) {
// Creating an object of Vector which contains
// elements of different data types
Vector<Object> vector = new Vector<>();
// Adding values to the Vector
vector.add("Let's");
vector.add("Contribute");
vector.add("to");
vector.add('G');
vector.add('F');
vector.add('G');
vector.add(3);
vector.add(12.054574);
// Displaying the values of the vector
System.out.println("The elements of the Vector is : "
+ vector);
// Creating the Enumeration of the Vector elements.
Enumeration enumeration = vector.elements();
// Now Enumerating through the Vector and printing
// each enumeration constant.
System.out.println(
"The output after Enumerating through the Vector : ");
while (enumeration.hasMoreElements()) {
System.out.println(enumeration.nextElement());
}
}
}
Output
The elements of the Vector is : [Let's, Contribute, to, G, F, G, 3, 12.054574]
The output after Enumerating through the Vector :
Let's
Contribute
to
G
F
G
3
12.054574
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