packageguru.springframework.blog.sortarraylist.ascendingdescending;importorg.junit.Test;importjava.util.ArrayList;importstaticorg.junit.Assert.*;publicclassSortArrayListAscendingDescendingTest{@TestpublicvoidtestSortAscendingDescending()throws Exception{ArrayList countryList=newArrayList<>();countryList.add("France"...
在 sortAscending()方法中,我们调用了 Collections.sort()方法,并传递这个初始化的 ArrayList对象为参数,返回排序后的 ArrayList。在 sortDescending()方法中,我们调用重载的 Collections.sort()方法让其按照降序对元素排序,这个版本的 Collections.sort()接收ArrayList对象作为第一个参数,一个由 Collections.reverseOrder(...
2. SortArrayListin Natural (Ascending) Order Thesort()is part of theListinterface and has been implemented inArrayListclass since Java 8. It takes aComparatorinstance used for enforcing the sorting order. Note thatArrayList.sort()method does the in-place sorting i.e. it modifies the original ...
SortArrayListAscDes sortArrayListAscDes = new SortArrayListAscDes(stringArrayListist); System.out.println("没有经过排序的数组: "+stringArrayListist); System.out.println("升序排序: "+ sortArrayListAscDes.sortAscending()); System.out.println("降序排序: "+ sortArrayListAscDes.sortDescending()); }...
In one of the previous examples, we covered how to sort an ArrayList in ascending order. In this post, you will learn how to sort ArrayList in descending order in Java. We will explore the following ways: Using the sort() method Using the Collections.sort() and Collections.reverse() ...
out.println("Sorted ArrayList in descending order: " + arrayList); } } 复制代码 如果你想使用Java 8的Lambda表达式进行排序,可以使用Collections.sort(arrayList, (a, b) -> b - a)。 注意:这些方法都会修改原始的ArrayList。如果你想保留原始列表并创建一个新的排序列表,可以使用new ArrayList<>(arrayList...
SortArrayListAscendingDescendingTest.java package guru.springframework.blog.sortarraylist.ascendingdescending; import org.junit.Test; import java.util.ArrayList; import static org.junit.Assert.*; public class SortArrayListAscendingDescendingTest { @Test public void testSortAscendingDescending() throws Exception...
package guru.springframework.blog.sortarraylist.ascendingdescending; import org.junit.Test; import java.util.ArrayList; import static org.junit.Assert.*; public class SortArrayListAscendingDescendingTest { @Test public void testSortAscendingDescending() throws Exception { ...
考虑一个ArrayList存储着以字符串形式存在的国名(country name),为了对这个ArrayList进行排序,你需要调用Collections.sort()方法,传递由国名构成的ArrayList对象。这种方法将按照自然顺序(按字母升序)对元素(国名)进行排序。让我们为此来写一段代码。 SortArrayListAscendingDescending.java package guru.springframework.blog....
若要进行降序排序,可以使用Collections.sort()方法的重载版本,并传入一个Comparator对象,该对象定义了排序的规则。这里可以使用Collections.reverseOrder()方法获取一个逆序的Comparator。 java Collections.sort(countryList, Collections.reverseOrder()); System.out.println("Sorted ArrayList in Descending Order: " + ...