public void funcName(List<String> param){ //dosomething } 以上函数中的参数，param就是一个List，元素类型为String。如果要限定上界或者下界，可使用Collection<? extends/super>这样的限定语法，不过用在你这里不合适，如果确定只有这两种类型，那么重载两个方法就可以了，一个接受Collection<Integer>...
*/ private static void testStringPoolGarbageCollection() { //first method call - use it as a reference test( 1000 * 1000 ); //we are going to clean the cache here. System.gc(); //check the memory consumption and how long does it take to intern strings //in the second method call...
Java集合类(如ArrayList,HashSet等)都重写了toString()方法,因此我们可以直接打印集合对象来获取其字符串表示。 importjava.util.ArrayList;importjava.util.HashSet;publicclassCollectionToStringExample{publicstaticvoidmain(String[]args){ArrayList<String>list=newArrayList<>();list.add("Apple");list.add("Banana"...
package _02Arrays.test02; import java.util.Arrays; public class Demo01 { public static void main(String[] args) { int[] arr = {1,332,43,25,3324,34,335,4,45,2,43,52,54}; //- 请打印数组所有元素 System.out.println(Arrays.toString(arr)); //- 请对数组元素进行“升序”排序 Arrays...
在项目和系统的开发中,为了提高方法的灵活度和可复用性,我们经常要传递不确定数量的参数到方法中,在Java 5之前常用的设计技巧就是把形参定义成Collection类型或其子类类型,或者是数组类型,这种方法的缺点就是需要对空参数进行判断和筛选,比如实参为null值和长度为0的Collection或数组。
主函数类MainDemo.java package com.itcast.test20140109; import java.util.ArrayList; import java.util.Collection; import java.util.Comparator; import java.util.Enumeration; import java.util.HashSet; import java.util.Iterator; import java.util.LinkedHashSet; ...
Collection.addAll(Collection) putAll public void putAll(StringTable that) Puts all of the nodes in the specified StringTable to this StringTable including the ones that are already present. This operation effectively modifies this StringTable so that its value is the union of the two ...
11 public TreeSet(Collection<? extends E> c) { 12 this(); 13 addAll(c); 14 } 15 public TreeSet(SortedSet<E> s) { 16 this(s.comparator()); 17 addAll(s); 18 } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.
codePointAt()Returns the Unicode value at an index (position) in a string concat()Returns two or more joined strings constructorReturns the string's constructor function endsWith()Returns if a string ends with a specified value fromCharCode()Returns Unicode values as characters ...
Methods declared in interface com.sun.jdi.ObjectReference disableCollection,enableCollection,entryCount,equals,getValue,getValues,hashCode,invokeMethod,isCollected,owningThread,referenceType,referringObjects,setValue,uniqueID,waitingThreads Methods declared in interface com.sun.jdi.Value ...