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How to count the number of time sum is = 7?

I have to make program to roll 2 dice 100 times, and count the # of time the sum equals 7.
I tried doing a count for loop to count the sums = 7, but think I'm getting off base somewhere in the logic of that.
// int i = 0; No. of rolls
// int count = 0; No. of rolls = to 7
for (int i = 0; i <= 100; i++){
int dice1 = randomGenerator.nextInt(7);
int dice2 = randomGenerator.nextInt(7);
int sum = (dice1 + dice2);
System.out.println(dice1 + ", " + dice2 + ", total: " + sum + " roll: " + i);
}
for (int count = 0; count++) {
System.out.println(count);
}
System.out.println("Total number of time sum equaled 7 was " + count);
I'm getting the random rolls, roll count, and sum of dice correctly, Just need to figure out how to add a sum = 7 count and I'm getting stuck.

Here's another answer using streams
public static void main(String[] args){
Random rng = new Random();
long result = IntStream
.generate(() -> rng.nextInt(6) + rng.nextInt(6) + 2)
.limit(100)
.filter(x -> x == 7)
.count();
System.out.println("Total number of time sum equaled 7 was " + result);
}

Just replace your for (int count = 0; count++) { ... } with if (sum==7) count++ and put it after int sum = (dice1 + dice2);
This increases count if the sum is 7 within the loop of your 100 double dice rolls.
To remove the wrong dice range (0-7, see comment #Robby Cornelissen) just do a randomGenerator.nextInt(6)+1.
int count = 0; // No. of rolls = to 7
for (int i = 0; i <= 100; i++){
int dice1 = randomGenerator.nextInt(6)+1;
int dice2 = randomGenerator.nextInt(6)+1;
int sum = (dice1 + dice2);
if (sum==7) count++;
System.out.println(dice1 + ", " + dice2 + ", total: " + sum + " roll: " + i);
}
System.out.println("Total number of time sum equaled 7 was " + count);

Using Java 8, program would look like this :
public class Dice
{
static int count = 0;
static Random ran = new Random();
public static void main(String[] args)
{
IntStream.rangeClosed(1, 100). // iterates 1 to 100
parallel().// converts to parallel stream
forEach(i -> {
rollDiceAndCheckIfSumIs7();
});// prints to the console
System.out.println("Out of 100 times, total number of times, sum was 7 is :" + count);
}
private static void rollDiceAndCheckIfSumIs7()
{
int dice1 = ran.nextInt(7);
int dice2 = ran.nextInt(7);
count += (dice1 + dice2 == 7) ? 1 : 0;
}
}

Having issues with dice probability program

I am trying to make a program that calculates dice rolls using random digits and returns the probability of each sum happening for different numbers of rolls and trials. This code however only results in probabilities of zero displaying. This seems to be an issue with the establishment of the match variable in the nested for loop. Wondering what I am doing wrong. Is it establishing the match variable based on the counter?
import java.util.Random;
import java.util.Scanner;
public class DiceProbability
{
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
Random randNumList = new Random();
System.out.println("How many sides do the dice have: ");
int diceSides = in.nextInt();
System.out.println("How many times will the dice be rolled: ");
int diceRolls = in.nextInt();
int highestSum = diceSides * 2;
int diceRoll1 = 0;
int diceRoll2 = 0;
int match = 0;
int totalOfDiceRolls = 0;
int counter = 0;
int counter2 = 0;
System.out.println("Rolls total " + "Probability");
for(counter=2;counter<=highestSum;counter ++)
{
for(counter2=1;counter2<=diceRolls;counter2 ++)
{
diceRoll1 = (randNumList.nextInt(11)+1);
diceRoll2 = (randNumList.nextInt(11)+1);
int totalOfRolls = diceRoll1 + diceRoll2;
if(totalOfDiceRolls != counter)
{
match = match + 0;
}
else
{
match ++;
}
}
System.out.println(match);
double probabilityOfSum = (match * 100 / diceRolls);
System.out.println(counter + ": " + probabilityOfSum);
counter2 = 1;
}
}
}

If I understand this correctly you are trying to calculate the relative frequency for each sum of two dices being rolled. If it's the case please edit your question as it's not that explicit in what your asking, especially that you have always two dices.
If you have two sided dices, your mathematical probability is as per below :
P(of having 2) = 1/4
P(of having 3) = 2/4
P(of having 4) = 1/4
All others are equal to 0.
Here is the code to achieve this. You need to save the frequency in an array and output correctly in dividing by the number of experiment.
Note: if you run this for a number less than 1000 this won't be accurate mathematically so it doesn't really make sense the user input the number of experiments in this case... ( in my opinion)
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.println("How many sides do one dice have: ");
int diceSides = in.nextInt();
int[] results = new int[diceSides * 2 + 1];
Random rnd = new Random();
for (int i = 0; i < 10000; i++) {
int resultdice1 = rnd.nextInt(diceSides) + 1;
int resultdice2 = rnd.nextInt(diceSides) + 1;
int sum = resultdice1 + resultdice2;
results[sum] = results[sum] + 1;
}
for (int i = 0; i < results.length; i++) {
System.out.println("Probability to have sum of " + i + " is : " + (double) results[i] / 10000);
}
}
Output :

Java-Number of scores needs to be one less in answer

So here is my code:
package e7;
import java.util.Scanner;
public class Q1 {
public static void main(String[] args)
{
double[] scores = new double[10];
double sum = 0.0D;
int count = 0;
Scanner sc = new Scanner(System.in);
do {
System.out.print("Enter a new score (-1 to end): ");
scores[count] = sc.nextDouble();
if (scores[count] >= 0.0D)
sum += scores[count];
}
while (scores[(count++)] >= 0.0D);
System.out.println("The total number of scores is: " + count );
double average = sum / (count - 1);
int numOfAbove = 0;
int numOfBelow = 0;
for (int i = 0; i < count - 1; i++) {
if (scores[i] >= average)
numOfAbove++;
else
numOfBelow++;
}
System.out.printf("Average is " + "%.2f\n",average);
System.out.println("Number of scores above or equal to the average " + numOfAbove);
System.out.println("Number of scores below the average " + numOfBelow);
}
}
How do make it display the correct number of scores calculated? If I input 2 numbers and then do the -1 one to end it keeps saying 3 scores. Should only be two. How do I fix this? Thanks

System.out.println("The total number of scores is: " + count );
You probably want:
System.out.println("The total number of scores is: " + (count - 1));

You could also change your loop from a do while to a while loop as follows,
while (true) {
System.out.print("Enter a new score (-1 to end): ");
double tempDouble = sc.nextDouble();
if (tempDouble >= 0.0D)
scores[count] = tempDouble;
sum += scores[count];
count++;
else
break;
}
That way as if your double input isn't correct it would break out of the while loop when the user entered -1. You might have to tweak it a bit for your use case.

control structure, repetition exercise: How to get the sum of the digits of a number?

Guys can you please help me answer this exercise using for loop without using string methods.
Write a program that prompts the user to input an integer and then outputs both the individual digits of the number and the sum of the digits. For example, the program should output the individual digits of 3456 as 3 4 5 6 and the sum as 18,and output the individual digits of -2345 as 2 3 4 5 and the sum as 14.
This is the code:
package MyPackage;
import java.util.*;
public class Integer
{
public static void main(String args[])
{
Scanner console = new Scanner (System.in);
int input;
int sum = 0;
int num1 = 0;
int counter = 1;
String num = "";
System.out.print("enter a number: ");
input = console.nextInt();
if (input == (-input))
{
input = input * (-1);
num = String.valueOf(input);
num1 = num.length();
System.out.print("the digits of " + input + " are: ");
for (int i = 0; i < num1; i++ )
{
String var = num.substring(i,counter);
int var1 = Character.getNumericValue(var.charAt(0));
System.out.print(var + " ");
sum = sum + var1;
counter++;
}
System.out.println();
System.out.println("the sum is: " + sum);
}
else
{
num = String.valueOf(input);
num1 = num.length();
System.out.print("the digits of " + input + " are: ");
for (int i = 0; i < num1; i++ )
{
String var = num.substring(i,counter);
int var1 = Character.getNumericValue(var.charAt(0));
System.out.print(var + " ");
sum = sum + var1;
counter++;
}
System.err.println();
System.out.println("the sum is: " + sum);
}
}
}

Iterating all the digits from right to left is easy enough - you just keep dividing by 10 and keeping the remainder.
Since you need to print them from left to right, but there don't seem to be any constraint on the memory usage, you could just keep them in a list, and print it backwards:
int num = ...; // inputed from user
List<Integer> digits = new LinkedList<>();
int sum = 0;
// Extract the digits and the sum
while (num != 0) {
int digit = num % 10;
digits.add (digit);
sum += digit;
num /= 10;
}
// Print backwards:
System.out.print ("The digits are: ");
for (int i = digits.size() - 1; i >= 0; --i) {
System.out.print (digits.get(i) + " ");
}
System.out.println();
System.out.println("Their sum is: " + sum);

Passing array through average method, resulting in low percent

For some reason the average is being populated wrong when I pass the array to the method I get a really low percent. It almost seems like since the Array shotsMade is only recording integers for made shots and not misses it is not calculating off the right base.
import java.util.*;
public class Test {
public static void main(String[] args) {
int myGameCounter = 1;
int shotCount = 0;
int shotCount1 = 0;
int [] shotsMade = new int [5];
int sum = 0;
System.out.print("Enter Player's Free Throw Percentage: ");
Scanner input = new Scanner(System.in);
int percent = input.nextInt();
//Game #1
System.out.println("Game " + myGameCounter + ":");
Random r = new Random();
myGameCounter++;
shotCount = 0;
for (int i = 0; i < 10; ++i){
boolean in = tryFreeThrow(percent);
if (in) {
shotCount++;
System.out.print("In" + " ");
}
else {
System.out.print("Out" + " ");
}
}
System.out.println("");
System.out.println("Free throws made: " + shotCount + " out of 10");
shotsMade[0]= shotCount;
//Game #2
System.out.println("");
System.out.println("Game" + myGameCounter + ":");
myGameCounter++;
shotCount1 = 0;
for (int i = 0; i < 10; ++i){
boolean in = tryFreeThrow(percent);
if (in) {
shotCount1++;
System.out.print("In" + " ");
}
else {
System.out.print("Out" + " ");
}
}
System.out.println("");
System.out.println("Free throws made: " + shotCount1 + " out of 10");
shotsMade[1]= shotCount1;
System.out.println("");
System.out.println("Summary:");
System.out.println("Best game: " + max(shotsMade));
System.out.println("Total Free Throws Made: " + sum(shotsMade) + " " + "out of 20");
System.out.println("Average Free Throw Percentage: " + average(shotsMade) +"%");
}//main
public static boolean tryFreeThrow(int percent) {
Random r = new Random();
int number = r.nextInt(100);
if (number > percent){
return false;
}
return true;
}
public static float average(int nums[]) {
int total = 0;
for (int i=0; i<nums.length; i++) {
total = total + nums[i];
}
float f = (total / nums.length);
return (float)total /(float)nums.length;
}
public static int sum(int nums[]) {
int sum = 0;
for (int i=0; i<nums.length; ++i) {
sum += nums[i];
}
return (int)sum;
}
public static int max(int nums[]) {
int max=nums[0];
for (int i=1; i<nums.length; i++) {
if (nums[i] > max)
max = nums[i];
}
return max;
}
}//class

You are calculating the avarage of 5 numbers but you only set 2. So if all shots hit your array will look like this: 10, 10, 0, 0, 0 and the avarage will be 4.

Old issue, you are using integer arithmetic total / nums.length with returns you an int value. You later assign it to a float, but the value already has been truncated.
Just change one of the values to float before the division, v.g. ((float) total) / num

Among others, your expression
float f = (total / nums.length);
will yield an inaccurate result.
Both total and nums.length are integers, and any operation between integers always results in an integer.
Example: if total=10 and nums.length=3, you'd expect the result to be 3.333... but actually the result is just 3. Only after that do you cast it to a float, resulting in 3.0.
To get the required result, you need to cast both integers to floats before dividing:
float f = (float) total / (float) nums.length;