list、map的遍历方式

迈不过友情╰ 2022-04-03 03:14 250阅读 0赞

list的remove()方法有2个  
remove(int index) 这个是下标  
remove(元素内容)

package com.smart.domain;
    
    import java.util.*;
    
    /**
     * @ProjectName chapter2
     * @ClassName ListRemove
     * @Description TODO
     * @Author jing
     * @Date 2018/12/20 10:35
     * @Version 1.0
     **/
    public class ListRemove {
    
        public static void main(String[] args) {
            //list遍历的三种方式
            //1.for循环
            List<String>  list =new ArrayList<String>();
            list.add("11");
            list.add("22");
            list.add("33");
            list.add("44");
            list.add("55");
            list.add("66");
            for (int i=0;i<list.size();i++){
                if(list.get(i).equals("11")){
                    list.remove(list.get(i));
                }
            }
            System.out.println("list是指"+list);
    
            List<String> list1=new ArrayList<String>();
            list1.add("11");
            list1.add("22");
            list1.add("33");
            list1.add("44");
            list1.add("55");
            list1.add("66");
            //2.增强for循环，foreach
            for(String str:list1){
                if(str.equals("22")) {
                    list.remove(str);
                }
            }
            System.out.println("list1是指"+list1);
            List list2=new ArrayList();
            list2.add("11");
            list2.add("22");
            list2.add("33");
            list2.add("44");
            list2.add("55");
            list2.add("66");
            //3.迭代器
            Iterator<String> iterator=list2.iterator();
            while(iterator.hasNext()){
                String x=iterator.next();
                if(x.equals("333")){
                    iterator.remove();
                }
            }
            System.out.println("list2是指"+list2);
            //map的遍历方式
            //1.通过map.keySet遍历key和value
            Map<String,String> map=new HashMap<String,String>();
            map.put("1","jp");
            map.put("2","juzi1");
            map.put("3","juzi12");
            map.put("4","juzi123");
            map.put("5","juzi1234");
            for(String key:map.keySet()){
                System.out.println("map的key"+key+"map的value"+map.get(key));
            }
            //迭代器遍历map.entryset
            Iterator iterator1=map.entrySet().iterator();
            while (iterator1.hasNext()){
                Map.Entry<String,String> entry= (Map.Entry<String, String>) iterator1.next();
                System.out.println("map的key是"+entry.getKey()+"map的value是"+entry.getValue());
            }
            //直接使用entrySet
            for (Map.Entry<String,String> entry:map.entrySet()){
                System.out.println("map的key是"+entry.getKey()+"map的value是"+entry.getValue());
            }
            //遍历所有的values
            for (String value:map.values()){
               System.out.println("The value"+value);
            }
        }
    
    
    }

结果

list是指[22, 33, 44, 55, 66]
    list1是指[11, 22, 33, 44, 55, 66]
    list2[11, 22, 33, 44, 55, 66]
    map的key1map的valuejp
    map的key2map的valuejuzi1
    map的key3map的valuejuzi12
    map的key4map的valuejuzi123
    map的key5map的valuejuzi1234
    map的key是1map的value是jp
    map的key是2map的value是juzi1
    map的key是3map的value是juzi12
    map的key是4map的value是juzi123
    map的key是5map的value是juzi1234
    map的key是1map的value是jp
    map的key是2map的value是juzi1
    map的key是3map的value是juzi12
    map的key是4map的value是juzi123
    map的key是5map的value是juzi1234
    The valuejp
    The valuejuzi1
    The valuejuzi12
    The valuejuzi123
    The valuejuzi1234