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User input never enters if statement

The point of the program is to have a user input an amount of integers endlessly (until they enter something other than an integer), and for each integer the user inputs, it should check if the integer is greater than or less than the value entered.
The problem: When the program runs, everything is fine until reaching
number = scanner.nextInt();
At this point, the user inputs their integer, but never makes it inside the following if statements. I would love a hint instead of an answer, but I'll take what I can get.
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
do {
System.out.println("Enter number: ");
int number = 0;
int minNumber = 0;
int maxNumber = 0;
boolean hasInt = scanner.hasNextInt();
if (hasInt) {
number = scanner.nextInt();
if (maxNumber < number) {
maxNumber = number;
}
if (minNumber > number) {
minNumber = number;
}
} else {
System.out.println("Your minimum number: " + number);
System.out.println("Your maximum number: " + maxNumber);
break;
}
} while (true);
scanner.close();
}
}

Your minNumber and maxNumber declarations should be out side of the loop. Also, you need to initialize the values as below to get correct min and max comparison with the entered values only:
int minNumber = Integer.MAX_VALUE;
int maxNumber = Integer.MIN_VALUE;
In print statement instead of minNumber you are printing number!

It's not reaching the if statements, because if it did, the user input would update to the value entered I would think. It doesn't. It outputs the values initially declared.
You're not getting the right output and you have a hypothesis that the cause is the code not entering the if statements. Following the scientific method, the next step is to test your hypothesis.
If you put printouts inside the if statements you'll see that they are indeed running. That's not it. The mistake must be elsewhere. You should collect more evidence and develop a new hypothesis.
Hint: Try printing out the values of your variables at the beginning and end of each iteration. I've marked the places below. Are they what you expect them to be? You're going to see an anomaly that should point you in the right direction.
do {
System.out.println("Enter number: ");
int number = 0;
int minNumber = 0;
int maxNumber = 0;
// Print number, minNumber, and maxNumber.
boolean hasInt = scanner.hasNextInt();
if (hasInt) {
number = scanner.nextInt();
if (maxNumber < number) {
maxNumber = number;
}
if (minNumber > number) {
minNumber = number;
}
} else {
System.out.println("Your minimum number: " + number);
System.out.println("Your maximum number: " + maxNumber);
break;
}
// Print number, minNumber, and maxNumber.
} while (true);

For loop to get user input lets you enter two values for the first question, but only calculates one value

I created a small program that asks the user for 10 random numbers and it will print the sum of those numbers. I embedded it with a for loop and included a counter. Everything seems to be working fine except when I run the program, the first question allows me to enter two values, but it will still only calculate a total of 10 numbers.
Below is what I currently have and I need to understand what is going wrong when it prompts the user for the number the first time:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int sum = 0;
int counter = 0;
for (int i = 0; i < 10; i++) {
counter++;
System.out.println("Enter number #" + counter + " :");
int numberInput = scanner.nextInt();
boolean hasNextInt = scanner.hasNextInt();
if (hasNextInt) {
sum += numberInput;
} else {
System.out.println("Invalid Number");
}
}
scanner.nextLine(); // handle the next line character (enter key)
System.out.println("The sum is " + sum);
scanner.close();
}
}

In each loop, you're calling scanner.nextInt() and scanner.hasNextInt(). But you do not use the result of hasNextInt() in a meaningful way (you might have noticed that your "Invalid Number" output is not what happens if you enter something that's not a number).
The first call to nextInt() blocks until you enter a number. Then hasNextInt() will block again because the number has already been read, and you're asking whether there will be a new one. This next number is read from System.in, but you're not actually using it in this iteration (you merely asked whether it's there). Then in the next iterations, nextInt() will not block because the scanner already pulled a number from System.in and can return it immediately, so all the subsequent prompts you see actually wait for input on hasNextInt().
This amounts to 11 total input events: The firts nextInt() plus all 10 hasNextInt()s

Scanner scanner = new Scanner(System.in);
int sum = 0;
int counter = 0;
for (int i = 0; i < 10; i++) {
counter++;
System.out.println("Enter number #" + counter + " :");
int numberInput = scanner.nextInt();
// boolean hasNextInt = scanner.hasNextInt();
//if (hasNextInt) {
sum += numberInput;
// } else {
// System.out.println("Invalid Number");
//}
}
scanner.nextLine(); // handle the next line character (enter key)
System.out.println("The sum is " + sum);
scanner.close();
Don't call hasnextInt() it has no use here.
It has taken 11 inputs rather than 10.
If you remove this condition it will take 10 inputs and work fine.
Your condition have no impact on it.

Terminating loops with strings. (Java)

Write a program that uses a while loop. In each iteration of the loop, prompt the user to enter a number – positive, negative, or zero. Keep a running total of the numbers the user enters and also keep a count of the number of entries the user makes. The program should stop whenever the user enters “q” to quit. When the user has finished, print the grand total and the number of entries the user typed.
I can get this program to work when I enter a number like 0, to terminate the loop. But I have no idea how to get it so that a string stops it.
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int count = 0;
int sum = 0;
int num;
System.out.println("Enter an integer, enter q to quit.");
num = in.nextInt();
while (num != 0) {
if (num > 0){
sum += num;
}
if (num < 0){
sum += num;
}
count++;
System.out.println("Enter an integer, enter q to quit.");
num = in.nextInt();
}
System.out.println("You entered " + count + " terms, and the sum is " + sum + ".");
}

Your strategy would be to get the input as a string, check to see if it is a "q", and if not convert to number and loop.
(Since this is your project, I am only offering strategy rather than code)
This is the rough strategy:
String line;
line = [use your input method to get a line]
while (!line.trim().equalsIgnoreCase("q")) {
int value = Integer.parseInt(line);
[do your work]
line = [use your input method to get a line]
}

public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int count = 0;
int sum = 0;
String num;
System.out.println("Enter an integer, enter q to quit.");
num = in.next();
while (!num.equals("q")) {
sum += Integer.parseInt(num);
count++;
System.out.println("Enter an integer, enter q to quit.");
num = in.next();
}
System.out.println("You entered " + count + " terms, and the sum is " + sum + ".");
}
Cuts down on your code abit and is simple to understand and gives you exactly what you want.
could also add an if statement to check if they entered another random values(so program doesn't crash if the user didn't listen). Something like:
if(isLetter(num.charAt(0))
System.out.println("Not an int, try again");
Would put it right after the while loop, therefore it would already of checked if it was q.

java expects an integer but we should give the same exception. One way to solve this problem is entering a String, so that if the user first pressing is the Q, never enters the cycle, if not the Q. We assume that the user is an expert and will only enter numbers and the Q when you are finished. Within the while we convert the String to number with num.parseInt (String)
Integer num;
String input;
while(!input.equal(q)){
num=num.parseInt(input)
if(num<0)
sum+=1;
else
sumA+=1;
}

Asking the user if they want to give multiple inputs

Im working on an assignment for an intro to java class and having some difficulty accounting for a situation when a user needs to give multiple inputs. The problem is given as follows:
"Ask the user to input a number. You should use an input dialog box for this input. Be sure to convert the String from the dialog box into a real number. The program needs to keep track of the smallest number the user entered as well as the largest number entered. Ask the user if they want to enter another number. If yes, repeat the process. If no, output the smallest and largest number that the user entered.
This program outputs the largest and smallest number AT THE END of the program when the user wants to quit.
Also, your program should account for the case when the user only enters one number. In that case, the smallest and largest number will be the same."
My issue is that I cannot figure out how to make the program continuously ask the user if they want to input another number....for as many times as they say yes (obviously). I know I will have to use a loop or something, but I am a beginner with this and do not know where to start. Any help would be appreciated, and thanks in advance!
Here is what I have so far:
package findingminandmax;
import javax.swing.JOptionPane;
public class Findingminandmax
{
public static void main(String[] args)
{
String a = JOptionPane.showInputDialog("Input a number:");
int i = Integer.parseInt(a);
String b = JOptionPane.showInputDialog("Would you like to input another number? yes or no");
if ("yes".equals(b)) {
String c = JOptionPane.showInputDialog("Input another number:");
int j = Integer.parseInt(c);
int k = max(i, j);
JOptionPane.showMessageDialog(null, "The maximum between " + i +
" and " + j + " is " + k);
} else {
JOptionPane.showMessageDialog(null, "The maximum number is " + i );
}
}
public static int max(int num1, int num2) {
int result;
if (num1 > num2)
result = num1;
else
result = num2;
return result;
}
}

String b = JOptionPane.showInputDialog("Would you like to input another number? yes or no");
while(b.equalsIgnoreCase("yes")){
String c = JOptionPane.showInputDialog("Input another number:");
// your logic
b = JOptionPane.showInputDialog("Would you like to input another number? yes or no");
}
// then have your logic to print maximum and minimum number
But to get Yes/No inputs use a Confirm dialogbox rather than a input dialogbox
e.g.
int b = JOptionPane.showConfirmDialog(null, "Would you like to input another number? yes or no", "More Inputs", JOptionPane.YES_NO_OPTION);
while (b == JOptionPane.YES_OPTION) {
// your logic
}

while(true) {
//do stuff
if ("yes".equals(b)) {
//do other stuff
} else { break; }
}

In Java, is it possible to use some sort of while loop (or anything) to determine the amount of prompts for input?

public static void main (String [] args)
{
// declare variables, capture input
String input, name = JOptionPane.showInputDialog("Please " +
"enter your first and last name.");
double testScore1, testScore2, testScore3, average;
// capture input, cast, and validate input
input = JOptionPane.showInputDialog("What is the score " +
"of your first test?");
testScore1 = Double.parseDouble(input);
while (testScore1 < 1 || testScore1 > 100)
{
input = JOptionPane.showInputDialog("This test score is not " +
"between 1 and 100. \nPlease enter a test score in " +
"this range:");
testScore1 = Double.parseDouble(input);
}
input = JOptionPane.showInputDialog("What is the score " +
"of your second test?");
testScore2 = Double.parseDouble(input);
while (testScore2 < 1 || testScore2 > 100)
{
input = JOptionPane.showInputDialog("This test score is not " +
"between 1 and 100. \nPlease enter a test score in " +
"this range:");
testScore2 = Double.parseDouble(input);
}
input = JOptionPane.showInputDialog("What is the score " +
"of your third test?");
testScore3 = Double.parseDouble(input);
while (testScore3 < 1 || testScore3 > 100)
{
input = JOptionPane.showInputDialog("This test score is not " +
"between 1 and 100. \nPlease enter a test score in " +
"this range:");
testScore3 = Double.parseDouble(input);
}
// calculate average and display output
average = (testScore1 + testScore2 + testScore3)/3;
JOptionPane.showMessageDialog(null, name + ", your average score is: " + average);
}
First off, I'm a beginner programmer. My terminology and jargon are quite lacking, so bear with me.
I'm writing a program to capture 3 test scores then validate them using a while loop (must be within the 1-100 range). The test scores are then averaged and the output displays the average. Pretty simple stuff.
I'm wanting to find a way, if possible, to capture the number of test scores, then from there, capture each actual score. For example, the program asks "How many tests are being computed for average?", then take that number and have it be the same amount of times the program prompts, "Please enter test score (1):" or something along those lines. So for further clarity, if the user typed 4 for number of tests, then the prompt for inputting the score would show up 4 times.
I feel the above code is redundant by using a while loop for each score and at that, limited because the program is only meant for 3 scores. Any help is much appreciated and feel free to critique anything else in the code.

Yes you can.
What you need is a nested loop. In pseudo code:
while(condition)
{
int numberOfInput = getInput() ; //get the input from the user
for(int i =0 ; i < numberOfInput; i++) //iterate for the amount of prompts required
prompt() ; //get input
}
function prompt
while (testScore1 < 1 || testScore1 > 100)
{
input = JOptionPane.showInputDialog("This test score is not " +
"between 1 and 100. \nPlease enter a test score in " +
"this range:");
testScore1 = Double.parseDouble(input);
}

Short answer:Yes, it is possible.
Option 1: Initially ask the user how many scores they are planning on entering, and store that in an int variable.
For example:
Ask user how many scores to enter.
Check the response, and store it in an int variable.
Create a double variable to add the scores (initialize it to 0.0)
Use a for loop, asking for the score;
Evaluate the score to ensure it's a valid number
If it's not a valid number, prompt the user again (this is still within
the same iteration, not a different iteration)
If it's a valid number, add it to the total scores variable
Once loop is exhausted, just divide the two variables (since the total
scores is a double, your answer will automatically be a double)
Display the answer.
Option 2: Use a sentinel-loop (the user has to enter a letter -usually 'Q' or 'N'- or something to exit the loop)
Create an int variable to store total loops (initialize to 0).
Create a double variable to add the scores (initialize it to 0.0)
Use a for loop, asking for the score;
Check if the value is the quit character
If it is not
Evaluate the score to ensure it's a valid number
If it's not a valid number, prompt the user again (this is still within
the same iteration, not a different iteration)
If it's a valid number, add it to the total scores variable and increment
the total loops variable by 1.
If it is
just divide the two variables (since the total
scores is a double, your answer will automatically be a double)
Display the answer.
Hope it helps.

In http://korada-sanath.blogspot.in/p/discussion-on-tech-topics.html, there is a pseudo code which illustrates similar problem with basic Java programming skills. In that in looping section you can simply add a check whether user entered score is in range 1-100 or not. If not, you can decrease loop variable by '1' so that user can enter his score one more time...
For further illustration please add below code in looping section of code present in above mentioned link.
instead of directly assigning user entered value to your testScores array, you can use one temp var and then can assign if user entered score in range.
Double temp = Double.parseDouble(br.readLine());
if(temp > 1 && temp < 100) {
testScores[loopVar] = temp;
} else {
loopVar--;
}