当您调用sc.nextLine()来读取coach时，它会遇到上一次nextLong()调用留下的换行符。因此，它读取一个空行（将换行符解释为输入行），并继续执行，而不允许您输入 coach name。
我的建议是始终使用nextLine()并转换为想要的Class，如下所示：

void accept() {
    System.out.println("Enter name , mobile number and coach for the customer and also the amount of ticket.");
    name = sc.nextLine();
    
    // Cast long value
    mobno = Long.valueOf(sc.nextLine());
    
    coach = sc.nextLine();
    
    // Cast int value
    amt = Integer.parseInt(sc.nextLine());
}

字符串

请看：

• InputMismatchException when using Sacnner nextLine for String
• Scanner is skipping nextLine() after using next() or nextFoo()?的

你也可以这样做：

void accept() {
    System.out.println("Enter name, mobile number, coach for the customer, and also the amount of ticket.");
    name = sc.nextLine();
    mobno = sc.nextLong();

    // Consume the remaining newline character in the input buffer
    sc.nextLine();

    coach = sc.nextLine();
    amt = sc.nextInt();
}

型