Jessica Benady

how do you convert lower case c to uppercase C without an appendix for the unicode library?
my prof told me it would be something like 'c'-'0' but I don't understand how that results in 'C'

could someone explain?

why is it better to use .equals() and not == to compare 2 strings?
if you use .equals() to compare 2 arrays, are you comparing the addresses in which the data is stored?

Thanks!

ahem, pardon the error is line 28!!

Thanks for your help, you were right I was missing a brace! Now I've added to the program and am once again getting errors, I'm sorry if these are really obvious mistakes, but I'm a beginner in java!
The errors are around line 21 & 22, where I have a nested loop and am asking the program to print digit and per[i] to the screen, the error says I'm missing a ")", but I don't think that's it, can anyone see my mistake?

public class BenfordsLaw{ public static void main(String[] args) { int firstdigit= calculateLeadingDigit(42); System.out.println("The first digit of your number is "+ firstdigit); double [] benfordNumbers = generateBenfordNumbers(200, .5, 3); int [] listLeadingDigitBenfordWholeNumbers = new int [benfordNumbers.length]; int leadingDigitBenfordNumbers; for (int i= 0;i< benfordNumbers.length; i++) { leadingDigitBenfordNumbers= calculateLeadingDigit((int) benfordNumbers[i]); //using these casted values for method in question 2 listLeadingDigitBenfordWholeNumbers [i] = leadingDigitBenfordNumbers; //making a new array that stores the answers (the leading numbers) from method in question 2 System.out.println (leadingDigitBenfordNumbers); } double [] listLeadingDigitBenfordDecimalNumbers = new double [listLeadingDigitBenfordWholeNumbers.length]; for (int i = 0; i< listLeadingDigitBenfordWholeNumbers.length; i++) { listLeadingDigitBenfordDecimalNumbers [i] = (double) listLeadingDigitBenfordWholeNumbers [i]; System.out.println (listLeadingDigitBenfordDecimalNumbers[i]); // storing back into a double array to use in question 4 } double [] per= calculatePercentage (listLeadingDigitBenfordDecimalNumbers); for (int digit=0; digit<10; digit++){ for (int i=0; i< benfordNumbers.length; i++) { System.out.println( "For Benford, the digit is " digit, "and the proportion is " + per[i]); } System.out.print(/n); } double distance = calculateDistance (new double[] {1,2,3}, new double[] {4,5,6}); } //Question 2, checked public static int calculateLeadingDigit (int number) { if (0<=number && number<=9) { return number; } int updatedNumber= Math.abs(number)/10; while (updatedNumber>=10) { updatedNumber= updatedNumber/10; } return updatedNumber; } //Question 3, checked public static double [] generateBenfordNumbers(double initialAmount, double growthRate, int numberPeriods) { System.out.println(" Generating Benford sequence with initial amount of " + initialAmount+ " dollars, " + growthRate + " growth per period, and " + numberPeriods+ " periods"); // printing values for Question 6 double [] generateBenfordNumbers = new double[numberPeriods]; generateBenfordNumbers[0] = initialAmount; int size = numberPeriods; for (int i= 1; i< size; i++){ generateBenfordNumbers [i]= generateBenfordNumbers[i-1]*(1+growthRate); } return generateBenfordNumbers; } //Question 4 public static double [] calculatePercentage ( double [] doubleArray){ double [] count; count = new double[10]; for (int i=0; i<10; i++){ count [i] = 0; } for ( int i=0; i< doubleArray.length; i++){ for ( int d= 0; d< 10; d++){ if (doubleArray [i]==d){ count[d]+=1; //could put i here? } } } //counts the occurrence of the leading digit values from 0-9 for (int i=0; i<10; i++){ System.out.print(count [i] + ","); } System.out.println(); double countDivisor= doubleArray.length; for (int i=0; i<10; i++){ count[i] = count[i]/(countDivisor); System.out.print(count[i] + ","); } System.out.println(); return(count); } //Question 5 public static double calculateDistance (double [] array1, double [] array2){ double sum = 0; for (int i = 0; i < array1.length; i++) { sum += Math.pow(array1[i] - array2[i], 2); } sum = Math.sqrt(sum); System.out.println (sum); return sum; } }

Would anyone be able to find errors in this code? It says that there is an illegal start of expression at line 31, but I suspect that there's probably something wrong in the way I wrote the code somewhere else, I simply can't find my mistake.



Thanks!



public class BenfordsLaw{ public static void main(String[] args) { int firstdigit= calculateLeadingDigit(42); System.out.println("The first digit of your number is "+ firstdigit); double [] benfordNumbers = generateBenfordNumbers(200, .5, 3); for (int i=0; i< benfordNumbers.length; i++) { System.out.println( "For Benford, the digit is " + benfordNumbers[i] + " ,"); } int [] listLeadingDigitBenfordWholeNumbers = new int [benfordNumbers.length]; int leadingDigitBenfordNumbers; double [] per= calculatePercentage (listLeadingDigitBenfordDecimalNumbers); for (int i= 0;i< benfordNumbers.length; i++) { leadingDigitBenfordNumbers= calculateLeadingDigit((int) benfordNumbers[i]); //using these casted values for method in question 2 listLeadingDigitBenfordWholeNumbers [i] = leadingDigitBenfordNumbers; //making a new array that stores the answers (the leading numbers) from method in question 2 System.out.println (leadingDigitBenfordNumbers); } double [] listLeadingDigitBenfordDecimalNumbers = new double [listLeadingDigitBenfordWholeNumbers.length]; for (int i = 0; i< listLeadingDigitBenfordWholeNumbers.length; i++) { listLeadingDigitBenfordDecimalNumbers [i] = (double) listLeadingDigitBenfordWholeNumbers [i]; System.out.println (listLeadingDigitBenfordDecimalNumbers[i]); // storing back into a double array to use in question 4 } double distance = calculateDistance (new double[] {1,2,3}, new double[] {4,5,6}); //Question 2, checked public static int calculateLeadingDigit (int number) { if (0<=number && number<=9) { return number; } int updatedNumber= Math.abs(number)/10; while (updatedNumber>=10) { updatedNumber= updatedNumber/10; } return updatedNumber; } //Question 3, checked public static double [] generateBenfordNumbers(double initialAmount, double growthRate, int numberPeriods) { System.out.println(" Generating Benford sequence with initial amount of " + initialAmount+ " dollars, " + growthRate + " growth per period, and " + numberPeriods+ " periods"); // printing values for Question 6 double [] generateBenfordNumbers = new double[numberPeriods]; generateBenfordNumbers[0] = initialAmount; int size = numberPeriods; for (int i= 1; i< size; i++){ generateBenfordNumbers [i]= generateBenfordNumbers[i-1]*(1+growthRate); } return generateBenfordNumbers; } //Question 4 public static double [] calculatePercentage ( double [] doubleArray){ double [] count; count = new double[10]; for (int i=0; i<10; i++){ count [i] = 0; } for ( int i=0; i< doubleArray.length; i++){ for ( int d= 0; d< 10; d++){ if (doubleArray [i]==d){ count[d]+=1; //could put i here? } } } //counts the occurrence of the leading digit values from 0-9 for (int i=0; i<10; i++){ System.out.print(count [i] + ","); } System.out.println(); double countDivisor= doubleArray.length; for (int i=0; i<10; i++){ count[i] = count[i]/(countDivisor); System.out.print(count[i] + ","); } System.out.println(); return(count); } //Question 5 public static double calculateDistance (double [] array1, double [] array2){ double sum = 0; for (int i = 0; i < array1.length; i++) { sum += Math.pow(array1[i] - array2[i], 2); } sum = Math.sqrt(sum); System.out.println (sum); return sum; } } }

Sorry I've only been using Java a couple of weeks, I've sorted that problem now, now I have a new one! This i my code for an assignment so far, it's a little messy..

import java.util.Scanner; public class BenfordsLaw{ public static void main(String[] args) { int firstdigit= calculateLeadingDigit(42); System.out.println("The first digit of your number is "+ firstdigit); double [] benfordNumbers = generateBenfordNumbers(200, .5, 3); System.out.println( "The amount of money accumulated after each period in time is " + benfordNumbers[2]); double [] testData = {2, 4324, 6564,88.443, -93204, 0.00, 1}; int [] benfordWholeNumbers = new int [benfordNumbers.length]; for (int i= 0;i< benfordNumbers.length; i++) // don't put less than or = ? { int benfordWholeNumbers [i]= (int) benfordNumbers[i]; } //now all benford numbers are in an int and can be used in method of question 2 int [] leadingDigitBenfordNumbers = calculateLeadingDigit(benfordWholeNumbers); //replace later with benfordNumbers for ( int i = 0; i<= leadingDigitBenfordNumbers.length; i++){ System.out.println(leadingDigitBenfordNumbers[i]); // creating variable and calling method of question 4, testing method replace testDat benfordNumbersa with } } //Question 2, checked public static int calculateLeadingDigit (int number) { if (0<=number && number<=9) { return number; } int updatedNumber= Math.abs(number)/10; while (updatedNumber>=10) { updatedNumber= updatedNumber/10; } return updatedNumber; } //Question 3, checked public static double [] generateBenfordNumbers(double initialAmount, double growthRate, int numberPeriods) { double [] generateBenfordNumbers = new double[numberPeriods]; generateBenfordNumbers[0] = initialAmount; int size = numberPeriods; for (int i= 1; i< size; i++){ generateBenfordNumbers [i]= generateBenfordNumbers[i-1]*(1+growthRate); } return generateBenfordNumbers; }



I havn't included the last bit because its incomplete, but when I try and compile this part it says '[' expected for line where I cast my double array into an int in the main method: " int [] benfordWholeNumbers = new int [benfordNumbers.length]; for (int i= 0;i< benfordNumbers.length; i++) // don't put less than or = ? { int benfordWholeNumbers [i]= (int) benfordNumbers[i]; }"


would anyone happen to know why?

Hi thank you for answering! Because when I run the program with the values 100, .1 and 4, I get this:

"The amount of money accumulated after each period in time is [D@50fba502"

which tells me somethings wrong.. would you happen to know what?

hey can anyone help me figure out what's wrong with my array method? its commented under Question 3

public class BenfordsLaw{ public static void main(String[] args) { int firstdigit= calculateLeadingDigit(-199); System.out.println("The first digit of your number is "+ firstdigit); double [] Sequence = {100, .1, 4}; System.out.println( "The amount of money accumulated after each period in time is " + Sequence); } //Question 2 public static int calculateLeadingDigit (int number) { if (0<=number && number<=9) { return number; } int updatedNumber= Math.abs(number)/10; while (updatedNumber>=10) { updatedNumber= updatedNumber/10; } return updatedNumber; } //Question 3 public static double [] generateBenfordNumbers(double initialAmount, double growthRate, int numberPeriods) { double [] Sequence = new double[numberPeriods]; Sequence[0] = initialAmount; int size = numberPeriods; for (int i= 1; i< size; i++){ Sequence [i]= Sequence[i-1]*(1+growthRate); } return Sequence; } }






Thanks!