java编程 扫描问题

public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
String b = scan.nextLine();
String [] a ={"a、添加","b、修改","c、删除","e、退出","1、图书馆信息管理","2、图书分类管理","3、图书信息管理","4、学生信息管理"};
for(int i =0;i String c = a[i].substring(0,1);
if(b.equals(c)){
System.out.println(a[i]);
}
}
}

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