Java数组,去掉重复值、增加、删除数组元素的方法

import java.util.List; 
import java.util.ArrayList; 
import java.util.Set; 
import java.util.HashSet; 
public class lzwCode { 
 
  public static void main(String [] args) { 
    testA(); 
    System.out.println("==========================="); 
    testB(); 
    System.out.println("==========================="); 
    testC(); 
  } 
 
  //去掉数组中重复的值 
  public static void testA() { 
    String [] str = {"Java", "C++", "Php", "C#", "Python", "C++", "Java"}; 
    for (String elementA:str ) { 
      System.out.print(elementA + " "); 
    } 
    List<String> list = new ArrayList<String>(); 
    for (int i=0; i<str.length; i++) { 
      if(!list.contains(str[i])) { 
        list.add(str[i]); 
      } 
    } 
    /* 
    Set<String> set = new HashSet<String>(); 
    for (int i=0; i<str.length; i++) { 
      set.add(str[i]); 
    } 
    String[] newStr = set.toArray(new String[1]); 
    */ 
    System.out.println(); 
    String[] newStr = list.toArray(new String[1]); //返回一个包含所有对象的指定类型的数组  
    for (String elementB:newStr ) { 
      System.out.print(elementB + " "); 
    } 
    System.out.println(); 
  } 
 
  //删除数组中其中一个元素 
  public static void testB() { 
    String [] str = {"Java", "C++", "Php", "C#", "Python"}; 
    for (String elementA:str ) { 
      System.out.print(elementA + " "); 
    } 
    //删除php 
    List<String> list = new ArrayList<String>(); 
    for (int i=0; i<str.length; i++) { 
      list.add(str[i]); 
    } 
    list.remove(2); //list.remove("Php")  
    System.out.println(); 
    String[] newStr = list.toArray(new String[1]); //返回一个包含所有对象的指定类型的数组  
    for (String elementB:newStr ) { 
      System.out.print(elementB + " "); 
    }   
    System.out.println(); 
  } 
 
  //在数组中增加一个元素 
  public static void testC() { 
    String [] str = {"Java", "C++", "Php", "C#", "Python"}; 
    for (String elementA:str ) { 
      System.out.print(elementA + " "); 
    } 
    //增加ruby 
    List<String> list = new ArrayList<String>(); 
    for (int i=0; i<str.length; i++) { 
      list.add(str[i]); 
    } 
    list.add(2, "ruby"); //list.add("ruby")  
    System.out.println(); 
    String[] newStr = list.toArray(new String[1]); //返回一个包含所有对象的指定类型的数组  
    for (String elementB:newStr ) { 
      System.out.print(elementB + " "); 
    }   
    System.out.println(); 
  } 
}