Thread: MORE java homework help.

The goal for this project was to allow a user to input the name and age of a person, as many times as they want, until they type "quit". After they type quit, the program is to print the name and age of the youngest person, and the oldest person. So far, I have a (probably not good) way for the user to input all the information and it moves to another method when the user types quit. I found a way to get all the ages to sort, but that's where I'm stuck. When I just print the array (which you see in my code) just to check how it sorts, it sorts a like 90 0's, then say 10 numbers in order.

I'm having a pretty hard time explaining this but hopefully someone can understand. Here is my code, now any help would be appreciated.

import java.util.*;
public class age {
public static void main(String[] args){
	Scanner keyboard = new Scanner(System.in);
	int[] personAge = new int[100];
	String[] personName = new String[100];
	int x = 0;
	char responseChar;
	responseChar = 'a';
 
	while(responseChar != 'q'){
		System.out.println("Please enter a name: ");
		personName[x] = keyboard.nextLine();
		responseChar = personName[x].charAt(0);
		if(responseChar == 'q'){
			sortAges(personAge);
		} else{
		System.out.println("Please enter their age: ");
		personAge[x] = keyboard.nextInt();
		keyboard.nextLine();
		++x;
		}
	}
}
public static void sortAges(int[] personAge){
	int sortAge[] = personAge;
	Arrays.sort(sortAge);
	System.out.println(Arrays.toString(sortAge));
}
}

I tried to understand what you were saying, and this is where I'm at now. I haven't got as far as making another class, thats going to be a whole nother story.

Anyways, why isn't the if statement inside my while loop working? And is that what I should be doing in that situation? But instead of going to sortAges() it should go to a method in another class?

Sorry, I forgot to attach code

	while(!"quit".equals(input)){
		System.out.println("Please enter a name: ");
		personName[x] = keyboard.nextLine();
		input = personName[x];
		if(input == "quit"){
			sortAges(personAge);
		}
		System.out.println("Please enter their age: ");
		personAge[x] = keyboard.nextInt();
		keyboard.nextLine();
		++x;
		}
	}

you should use "quit".equals(input)

Regards,
Chris

youre using equality operator to compare Strings?

if thats the case.. then im not so different with you regarding with your concern i also encountered that problem when comparing Strings until sir JSon told me and saw one of the posts here that states that

never use '==' or '!=' to compare Strings, i dont know why is it like that.... i dont know if theres anything to do with the logical circuitry of the system when it comes in java compiler (hahahaha )
always use '.equals()' method to compare Strings and use '!' (exclamation) to negate the value of it...

also if you want the input of strings ignore the case (no matter what the case is) use
'.equalsIgnoreCase'


ill share you my little knowledge 'bout that

if (input.equalsIgnoreCase("stop"));

either you enter "STOP" or "stop" your condition will return a true value.

Today in class I was wondering why he STILL wasn't talking about arrays and the assignment was due on Friday, and I found out I actually skipped a chapter and just assumed we were supposed to do the assignment with arrays. After finding that out, this program was simple. Since you guys are helping me, this probably isn't of use, but if anyone is interested here is how I figured it out.

import java.util.*;
public class age {
	public static void main(String[] args){
		Scanner stdin = new Scanner(System.in);
		String tempName;
		String oldName = "";
		String youngName = "";
		int tempAge;
		int oldAge = 0;
		int youngAge = 200;
		String input = "";
 
		while(!"quit".equalsIgnoreCase(input)){
			System.out.println("Please enter a name: ");
			tempName = stdin.nextLine();
			input = tempName;
			if("quit".equalsIgnoreCase(input)){
				System.out.println("The oldest person is " + oldName + ", who is " + oldAge + " years old.");
				System.out.println("The youngest person is " + youngName + ", who is " + youngAge + " years old.");
			} else {
				System.out.println("Please enter an age: ");
				tempAge = stdin.nextInt();
				stdin.nextLine();
				if(tempAge > oldAge){
					oldAge = tempAge;
					oldName = tempName;
			} else if(tempAge < youngAge){
				youngAge = tempAge;
				youngName = tempName;
				}
			}
		}
	}
}