Java Vector sureCapacity()
Java Vector类的
ensureCapacity()方法用于增加正在使用的vector的容量。 ，如有必要。这样可以确保向量至少可以容纳最小容量参数指定的分量数量。
语法:
以下是
ensureCapacity的声明。()方法:
Public void ensureCapacity(int minCapacity)
参数:
| DataType |
参数 |
说明 |
必需/可选 |
| int |
minCapacity |
这是所需的最小容量。 |
必需 |
返回:
ensureCapacity()方法的返回类型为void，因此它不返回任何内容。
例外:
NA
兼容版本:
Java 1.2及更高版本
示例1:
import java.util.*;
public class VectorEnsureCapacityExample1 {
public static void main(String arg[]) {
//Create an empty vector of capacity 10
Vector<Integer> vec = new Vector<>(10);
//Ensuring capacity
vec.ensureCapacity(25);
//Cheking the capacity
System.out.println("Minimum capacity of this vector: " +vec.capacity());
}
}
输出:
Minimum capacity of this vector: 25
示例2:
import java.util.*;
public class VectorEnsureCapacityExample2 {
public static void main(String arg[]) {
//Create an empty vector of capacity 10
Vector<String> vecobject = new Vector<>();
//Add element in the vector
vecobject.add("50");
vecobject.add("green");
vecobject.add("red");
System.out.println("Element: "+vecobject);
System.out.println("Capacity of the vector is: " +vecobject.capacity());
//Increases the capacity of this vector
vecobject.ensureCapacity(20);
System.out.println("New Capacity of the vector is:" +vecobject.capacity());
}
}
输出:
Element: [50, green, red]
Capacity of the vector is: 10
New Capacity of the vector is:20
示例3:
import java.util.*;
public class VectorEnsureCapacityExample3 {
public static void main(String arg[]) {
//Create an empty vector of capacity 10
Vector<Integer> vec = new Vector<>(5);
for (int i = 0; i < 10; i++) {
vec.add(0,i);
}
System.out.println("Element of the vector: "+vec);
System.out.println("Vector size: "+vec.size());
//Ensure the capacity of the vector and add elements
vec.ensureCapacity(40);
for (int i = 0; i < 10; i++) {
vec.add(0,i);
}
System.out.println("Vector element after ensuring capacity: "+vec);
System.out.println("New vector size: "+vec.size());
}
}
输出:
Element of the vector: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
Vector size: 10
Vector element after ensuring capacity: [9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
New vector size: 20
