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();

}

}

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