问题描述:
如何颠倒数组列表?
解决方案:
用Collections.reverse(ArrayList)函数,举例说明颠倒数组表方法:
例1:输入下列代码:
import java.util.ArrayList;
import java.util.Collections;
public class Main {
public static void main(String[] args) {
ArrayList arrayList = new ArrayList();
arrayList.add("A");
arrayList.add("B");
arrayList.add("C");
arrayList.add("D");
arrayList.add("E");
System.out.println("Before Reverse Order: " + arrayList);
Collections.reverse(arrayList);
System.out.println("After Reverse Order: " + arrayList);
}
}
结果:
Before Reverse Order: [A, B, C, D, E]
After Reverse Order: [E, D, C, B, A]
例2:输入下列代码:
public class HelloWorld {
public static void main(String[] args) {
int[] numbers = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
System.out.println("Array before reverse:");
for (int i = 0; i < numbers.length; i++) {
System.out.print(numbers[i] + " ");
}
for (int i = 0; i < numbers.length / 2; i++) {
int temp = numbers[i];
numbers[i] = numbers[numbers.length - 1 - i];
numbers[numbers.length - 1 - i] = temp;
}
System.out.println("\nArray after reverse:");
for (int i = 0; i < numbers.length; i++) {
System.out.print(numbers[i] + " ");
}
}
}
结果:
Array before reverse:
1 2 3 4 5 6 7 8 9 10
Array after reverse:
10 9 8 7 6 5 4 3 2 1