Java数组，去掉重复值、增加、删除数组元素

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();
}
}