Thread: learning the try and catch

Hey everyone, I'm taking a java class and this is 3rd week. Right now we are learning about arrays and using the try/catch. What I need help with is with this code below, I am trying to just display information about buildings. The application is good but not with the try and catch statement. I'm trying to just display the message of "please enter a building number" when a user puts a letter instead of a number(InputMismatchException) and then the user would have to put in one of the numbers. But when it runs and i put in a letter, it reads the message, but it always outputs the first building information, any help? thanks

package username;
import java.util.InputMismatchException;
import java.util.Scanner;
 
//TallBuildings
public class TallBuildings {
//compare heights of buildings
	public static void main(String[] args)
	{		
		//create local variables
		int i = 0;
		int b = 0;
		Scanner scanIn = new Scanner(System.in);
 
		//create building array
		Building[] bldgs = new Building[5];
 
		//create 5 buildings and save in array
		bldgs[0] = new Building();
		bldgs[0].name = "Sky Tower";
		bldgs[0].location = "China";
		bldgs[0].year = 2013;
		bldgs[0].height = 2750;
 
		bldgs[1] = new Building();
		bldgs[1].name = "Sears Tower";
		bldgs[1].location = "Chicago";
		bldgs[1].year = 21974;
		bldgs[1].height = 1451;
 
		bldgs[2] = new Building();
		bldgs[2].name = "One World Trade Center";
		bldgs[2].location = "New York";
		bldgs[2].year = 1972;
		bldgs[2].height = 1368;
 
		bldgs[3] = new Building();
		bldgs[3].name = "Empire State Building";
		bldgs[3].location = "New York";
		bldgs[3].year = 1931;
		bldgs[3].height = 1250;
 
		bldgs[4] = new Building();
		bldgs[4].name = "Chrysler Building";
		bldgs[4].location = "New York";
		bldgs[4].year = 1930;
		bldgs[4].height = 1046;
 
		//display the 5 buildings
		while (i < 5) {
			System.out.println((i+1) + "-" + bldgs[i].name);
			i++;
		}
 
		//ask user which building they want
		try {
			System.out.println("\nWhat building information do you need?");
			b = scanIn.nextInt();
			b--;
		} catch(InputMismatchException ime) {
			System.out.println("Please enter in a building number");
		}
 
		//Display building information
		System.out.println(bldgs[b].name);
		System.out.println(bldgs[b].location);
		System.out.println(bldgs[b].year);
		System.out.println(bldgs[b].height);

What do you want the program to do when there is an exception?
If you want it to go back and ask the user to input a valid value, you need to use a loop that exits when a valid value is entered and loops back when the input is invalid.

You need to answer this question first:
What do you want the program to do when there is an exception?
then decide how to do it.

allow the user to input one of the 5 building numbers again

Doing something "again" is what loops are for. If your assignment requires the code to do things "again" then you need to use a loop.

See the tutorial: The while and do-while Statements (The Java™ Tutorials > Learning the Java Language > Language Basics)