数组去掉重复值、删除元素、添加元素

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(); } }