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动力节点动力节点口口相传的java黄埔军校2019.01.23回答HashMap的常用方法map的存储和修改方式map.put(key,value);map是否包含某个元素map.containsKey(key);map某个key的value值map.get(key);参考代码importjava.util.HashMap;publicclassBookTest{staticHashMap<String,Integer>map=newHashMap<String,Integer>();static{//初始化图书信息map.put("三国志",8);map.put("红楼梦",0);map.put("西游记",15);}publicstaticvoidmain(String[]args){//main方法jieShu("水浒");jieShu("三国志");huanShu("三国志");jieShu("红楼梦");huanShu("红楼梦");jieShu("红楼梦");}publicstaticvoidjieShu(Stringname){//借书if(!map.containsKey(name)){//查询图书馆是否有这本书System.out.println("书籍:"+name+"\t查无此书!");return;}if(map.get(name)<=0){//查询图书数量是否为0System.out.println("书籍:"+name+"\t已全部借出,请明日在来");return;}map.put(name,map.get(name)-1);System.out.println("书籍:"+name+"\t借书成功。"+"\t库存:"+map.get(name));}publicstaticvoidhuanShu(Stringname){//还书if(!map.containsKey(name)){System.out.println("查无此书");}else{map.put(name,map.get(name)+1);System.out.println("书籍:"+name+"\t还书成功。"+"\t库存:"+map.get(name));}}}测试输出书籍:水浒查无此书!书籍:三国志借书成功。库存:7书籍:三国志还书成功。库存:8书籍:红楼梦已全部借出,请明日在来书籍:红楼梦还书成功。库存:1书籍:红楼梦借书成功。库存:0