最赞回答 / qq_慕工程040105
public class Student { public String id; public String name; public Set<Course> courses; public Student(String id,String name){ this.id = id; this.name = name; this.courses = new HashSet<Course>(); }}
2019-07-12
最新回答 / 慕仙7584962
byte[] str=s.getBytes(); for (int i=0;i<str.length;i++) { if (str[i]=='a'){ num++; }
2019-07-08