为什么以下代码不能捕获异常 [英] Why the following code doesn't catch the exception

问题描述

为什么以下代码在用户输入字母时未捕获异常。相反，如果用户输入的数字不是给定的选择，则会触发异常。



这不是完整的代码。



我尝试过：

 while（true）{
系统。 out.println（吸引力的\\\
List：）; 
 System.out.println（\ nSport：[1] Ferringhi Sea Sports Co.）; 
 System.out.println（文化：[2]槟榔土生华人博物馆）; 
 System.out.println（商店：[3] Queensbay Mall）; 
 System.out.println（食物：[4] Restoran Nasi Kandar Line Clear）; 
 System.out.println（[5]退出）; 
 System.out.print（\ n输入吸引力的更多细节：）; 
 int typeID = input.nextInt（）; 
 
 // Sport s = new Sport（1，ESCAPE Theme Park，139.58，828 Jalan Teluk Bahang，Teluk Bahang，Penang Island 11050，Malaysia，4.5）; 
尝试{
 if（typeID == 1）
 {
a [0] = new Sport（typeID，Ferringhi Sea Sports Co.，9 AM-7：30PM ，Wave Runner Watersport，Foot Reflexology& Fish Spa，Batu Ferringhi，George Town，Penang Island，Malaysia，4.7）; 
 System.out.println（a [0]）; 
} 
 else if（typeID == 2）
 {
a [1] = new Culture（typeID，Pinang Peranakan Museum， -  Adult（RM20.00）\\ -Child 6以下（免费），29，Church St，George Town，10200 George Town，Pulau Pinang，2楼，周一至周日，包括公众假期，上午9:30至下午5点 ，4.4）; 
 System.out.println（a [1]）; 
} 
否则if（typeID == 3）
 {
a [2] =新店铺（typeID，Queensbay Mall，该商场有5个零售级别的国际和本土品牌包括时尚，生活方式，餐饮，娱乐，体育，电子，家居和百货商店。，1F-78 Queensbay Mall，100 Persiaran Bayan Indah Bayan Lepas，11900 George Town，Penang，10:30 AM -10：30PM，4.4）; 
 System.out.println（a [2]）; 
} 
 else if（typeID == 4）
 {
a [3] = new Food（typeID，Restoran Nasi Kandar Line Clear，6.50 for a rice of rice ，炸鸡，鸡蛋，蔬菜和混合的肉汁，在161和177槟城路，乔治城，10000乔治城，Pulau Pinang，24小时，3.6）; 
 System.out.println（a [3]）; 
} 
 else if（typeID == 5）
 break; 
 else 
抛出新的InputMismatchException（）; 
} 
 catch（InputMismatchException ex）
 {
 System.out.println（输入错误：错误的输入！）; 
 input.nextLine（）; 
} 
} //结束while1循环for city1 

解决方案

你应该抓住<抛出的异常code> Scanner.nextInt 方法。

您的尝试位置错误。它应该是：

  while （true）{
 System.out.println（< span class =code-string>  \ n吸引力列表：）; 
 System.out.println（  \ nSport：[1] Ferringhi Sea Sports Co。）; 
 System.out.println（ 文化：[2] Pinang Peranakan Museum）; 
 System.out.println（ 商店：[3] Queensbay Mall）; 
 System.out.println（ 食物：[4] Restoran Nasi Kandar Line Clear ）; 
 System.out.println（  [5]退出）; 
 System.out.print（  \ n输入引用号码以获取更多详情：）; 
 尝试 {
  int  typeID = input.nextInt（）; 

Why the following code doesn't catch the exception when user entered letter. Instead, the exception caught if user entered a number other than the choice given.

This is not a full code.

What I have tried:

while(true) {
			System.out.println("\nList of Attraction: ");
			System.out.println("\nSport: [1]Ferringhi Sea Sports Co.");
			System.out.println("Culture: [2]Pinang Peranakan Museum");
			System.out.println("Shops: [3]Queensbay Mall");
			System.out.println("Food: [4]Restoran Nasi Kandar Line Clear");	
			System.out.println("[5] Exit");			
			System.out.print("\nEnter no. of attraction for more details: ");
			int typeID = input.nextInt();
			
			//Sport s = new Sport(1, "ESCAPE Theme Park", 139.58, "828 Jalan Teluk Bahang, Teluk Bahang, Penang Island 11050, Malaysia", 4.5);
			try {
			if(typeID==1)
			{
				a[0] = new Sport(typeID, "Ferringhi Sea Sports Co.", "9AM-7:30PM", "Wave Runner Watersport, Foot Reflexology & Fish Spa", "Batu Ferringhi, George Town, Penang Island, Malaysia", 4.7);
				System.out.println(a[0]);
			}
			else if(typeID==2)
			{
				a[1] = new Culture(typeID, "Pinang Peranakan Museum", "-Adult (RM20.00)\n\t   -Child below 6 (Free)", "29, Church St, George Town, 10200 George Town, Pulau Pinang, Floor 2", "Monday to Sunday including Public Holidays from 9:30 am to 5 pm", 4.4);
				System.out.println(a[1]);
			}
			else if(typeID==3)
			{
				a[2] = new Shops(typeID, "Queensbay Mall", "The mall features 5 retail levels of international and home-grown brands including fashion, lifestyle, dining, entertainment, sports, electronics, home furnishing and department store.", "1F-78 Queensbay Mall, 100 Persiaran Bayan Indah Bayan Lepas, 11900 George Town, Penang", "10:30AM-10:30PM", 4.4);
				System.out.println(a[2]);
			}
			else if(typeID==4)
			{
				a[3] = new Food(typeID, "Restoran Nasi Kandar Line Clear", "6.50 for a plate of rice, fried chicken, egg, vegetables and a mix of gravies", "Beside 161 & 177 Penang Road, George Town, 10000 George Town, Pulau Pinang", "24 hours", 3.6);
				System.out.println(a[3]);
			}
			else if(typeID==5)
				break;
			else
				throw new InputMismatchException();
			}
			catch(InputMismatchException ex)
			{
				System.out.println("Input Error: Wrong Input!");
				input.nextLine();
			}
			} // end while loop for city1

解决方案

You should catch the exception thrown by the Scanner.nextInt method.

Your try is in the wrong place. It should be:

while(true) {
			System.out.println("\nList of Attraction: ");
			System.out.println("\nSport: [1]Ferringhi Sea Sports Co.");
			System.out.println("Culture: [2]Pinang Peranakan Museum");
			System.out.println("Shops: [3]Queensbay Mall");
			System.out.println("Food: [4]Restoran Nasi Kandar Line Clear");	
			System.out.println("[5] Exit");			
			System.out.print("\nEnter no. of attraction for more details: ");
    try {
			int typeID = input.nextInt();

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