数组中元素增加、删除、去重

package test;

import java.util.ArrayList;
import java.util.List;

public class TestOfArrayOperate {
	
	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"};
        System.out.print("原始数组：");
        for (String elementA : str ) {
            System.out.print(elementA + " ");
        }
        System.out.print("\n");
        List<String> list = new ArrayList<String>();
        for (int i=0; i<str.length; i++) {
            if(!list.contains(str[i])) {
                list.add(str[i]);
            }
        }
        //返回一个包含所有对象的指定类型的数组
        String[] newStr =  list.toArray(new String[1]); 
        System.out.print("去重后的数组：");
        for (String elementB : newStr ) {
            System.out.print(elementB + " ");
        }
        System.out.println();
    }
    
    //删除数组中其中一个元素,删除php
    public static void testB() {
        String [] str = {"Java", "C++", "Php", "C#", "Python"};
        List<String> list = new ArrayList<String>();
        for (int i=0; i<str.length; i++) {
            list.add(str[i]);
        }
//      list.remove(2); //根据index删除
        list.remove("Php");   //根据内容删除
        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 string : newStr) {
			System.out.println(string + " ");
		}
    }
    
    //在数组中增加一个元素,增加ruby
    public static void testC() {
        String [] str = {"Java", "C++", "Php", "C#", "Python"};
        List<String> list = new ArrayList<String>();
        for (int i=0; i<str.length; i++) {
            list.add(str[i]);
        }
        list.add(2, "ruby"); //在第二个位置添加"ruby"
        list.add("ruby"); //在list尾部增加"ruby"
        //返回一个包含所有对象的指定类型的数组 
        String[] newStr =  list.toArray(new String[1]); 
        for (String string : newStr) {
			System.out.println(string + " ");
		}
    }
}


运行结果：

原始数组：Java C++ Php C# Python C++ Java 
去重后的数组：Java C++ Php C# Python 
===========================
Java 
C++ 
C# 
Python 
===========================
Java 
C++ 
ruby 
Php 
C# 
Python 
ruby