Java数组,去掉重复值、增加、删除数组元素的实现方法

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();	}}