java速度入门三

数组操作：

compareNew.java

//use the function:sort();binarySearch();fill();equals(); import java.util.Arrays; import java.util.Comparator; //define a class that we could ignore the letter's case when sort array class compareNew implements Comparator {     public int compare(Object o1,Object o2)     {         String s1=(String)o1;         String s2=(String)o2;         return s1.toLowerCase().compareTo(s2.toLowerCase());     }     }

array.java public class array {         public static void main(String args[])     {         int[] aa=new int[10];         String[] ss=new String[]{"w1","dwT","Aqs","Cda","Bsw","bss"};         //filling the array         Arrays.fill(aa,10);         System.out.println("array a: ");         for(int i=0;i<aa.length;i++)         {             System.out.print(aa[i]);                     }         System.out.println();         System.out.println("array ss: "+Arrays.asList(ss));         //sort array by the default setting         Arrays.sort(ss);         System.out.println("After sorting ss: "+Arrays.asList(ss));         System.out.println("Hello,java!");         //sort array by the our own function         Arrays.sort(ss,new compareNew());         System.out.println("Another sorting ss: "+Arrays.asList(ss));         int location=Arrays.binarySearch(ss, "w1");         System.out.println("The location of w1 is "+(location+1)+"!");     } } 简单实现了数组的搜索，查找，排序。

字符串操作：

Apple.java

//test the connect of String and object public class Apple {  private String name;  public String getName()  {      return name;  }  public void setName(String s)  {      this.name=s;  }  public String toString()  {      String str="I'm an apple,my name is "+name;      return str;  }  public static void main(String[] args)  {      Apple object=new Apple();      object.setName("App");      System.out.println("Hello,"+object);      } }

TestStringBuilder.java

//The useage of StringBuilder import java.lang.*; public class TestStringBuilder {     public static void main(String[] args)     {         String s="";         StringBuilder builder=new StringBuilder();         long startTime,endTime;         System.out.println("Please wait。。。");         //use the default function         startTime=System.currentTimeMillis();         for(int i=0;i<10000;i++) s+=i;         endTime=System.currentTimeMillis();         System.out.println("The cost of time: "+(endTime-startTime));         //use StringBuilder         startTime=System.currentTimeMillis();         for(int i=0;i<10000;i++) builder.append(i+"");         endTime=System.currentTimeMillis();         System.out.println("The cost of time by StringBuilder: "+(endTime-startTime));             } } 运行结果： Please wait。。。 The cost of time: 1371 The cost of time by StringBuilder: 9

主要要说一下字符串和对象的连接，默认是执行对象的toString方法，即将对象的全路径名称和地址，上面重载了toString方法。

第二个class是StringBuilder的用法，似乎会很快！