JAVA CODE NEEDED!

The formNum() method has to be rewritten so that it scans from left to right when it encounters the leftmost digit of a number or a leading decimal point. Of course the method of building up the double value from the successive digits has to be adjusted since you are scanning from left to right- try some examples to discover the correct approach

MY CODE:

import java.util.Scanner;

//class for evaluating arithmetic expressions public class Expr { Scanner kb = new Scanner(System.in);

//variables for an Expr object private String e; private int p; //pointer to characters within the expression string e private int len;

//constructor public Expr() { System.out.println("Enter an expression"); e = kb.nextLine(); //input a string as a line of keyboard input. len = e.length(); p = len-1; //position pointer at right end of the expression }

//print the current character and advance the pointer (to the left) public void printChar() { System.out.println(e.charAt(p)); p = p-1; }

public String getExpr() { return e; }

public int getp() { return p; }

public void setp(int pp) { p = pp; }

//if string e represents a number (possibly with a decimal point, possibly negative), //return the numerical value of the string as a double value public double formNum() { double total = 0.0; int count = 0; int flag = 0; double mult = 1.0; char c,d; do { c = e.charAt(p); //examine the current character in the string (from right to left) if(c == '.') { flag = 1; //set a flag to remember that the character is a decimal point } else { //if the current character is a digit, convert to its //int value and include it in the value corresponding to the string. if((c >= '0') && (c<= '9')) { total = total + mult*(c-'0'); mult = mult*10.0; if(flag==0) { count++; //count the number of digits to the right of a possible decimal point } } else { if(c == '_') { total = -total; //an underscore character represents a negative value } } } p--; //prepare to move to the next character to the left d = '?'; if(p>= 0) { d = e.charAt(p); //the next character to the left } }while((p>=0) && (((d<='9')&&(d>='0'))||(d=='_')||(d=='.')));//check for a valid character if(flag==1) { total = total/Math.pow(10.0,count*1.0); //compute the value taking into account //the number of decimal places } return total; } }