我一直试图让我的程序正常运行，尽管由于某种原因它还没有运行。我几乎可以肯定一切都可以工作，直到达到if循环来实际执行计算。由于某些奇怪的原因，当我做op.equals（加号）或我想测试的任何操作时，它只是不承认它们是相等的。我尝试了无数的变化，看看它们是否有效，但我仍然没有成功。我真的很感激，如果有人可以查看我的代码，也许可以进行更正或修复它。
public class FracCalc {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int repeat = 1;
while (repeat == 1) {
System.out.println("Input your equation");
String equation = input.nextLine(); // Takes the user input and sets it equal to a variable (equation)
produceAnswer(equation);
if(equation.equals("quit")) { // If the user inputs 'quit'
System.out.println("You've quit out of the calculator.");
repeat = 2; // repeat is set to 2 so the program can no longer run and it terminates.
}
}
}
public static String produceAnswer(String input) {
Scanner fraction = new Scanner(input);
String num1 = fraction.next();
String op = fraction.next();
String num2 = fraction.next();
// Creates an empty string for each necessary variable for values to be added to them later on.
String plus = "+";
String multiply = "*";
String division = "/";
String subtract = "-";
String whole = "";
String numer = "";
String denom = "";
String whole2 = "";
String numer2 = "";
String denom2 = "";
// Creates variables ansnum and ansden to be manipulated later on in the calculations.
int ansnum = 0;
int ansden = 0;
// Creates place and place2 to act as counters to go through each token of the original equation input.
int place = 0;
int place2 = 0;
String input1 = ""; // Sets an empty string variable for the return.
if(num1.contains("_")) { // If the first fraction contains an _
while(num1.charAt(place) != '_') { // while the place (index) isn't equal to that _
whole += num1.charAt(place); // Set everything before it, equal to whole.
place++; // Each time increase the place (index) by 1.
}
place++; // Increases the place by 1 to pass the _ and move onto the next part of the fraction
if(num1.contains("/")) { // If the first fraction contains a forward slash
while(num1.charAt(place) != '/') { // While the place does not equal its index
numer += num1.charAt(place); // Add every thing before it to a variable called numer
place++; // Each time increases the place (index) by 1.
}
place++; // Increases the place by 1 to pass the / and move onto the denominator.
}
while(place != num1.length()) { // While the place (index) is less than the length of fraction 1
denom += num1.charAt(place); // Add every thing before it equal to the denom variable.
place++; // Each time increases the place (index) by 1.
}
place++;
// Same process as above is repeated for fraction 2.
if(num2.contains("_")) {
while(num2.charAt(place2) != '_') {
whole2 += num2.charAt(place2);
place2++;
}
place2++;
if(num2.contains("/")) {
while(num2.charAt(place2) != '/') {
numer2 += num2.charAt(place2);
place2++;
}
place2++;
}
while(place2 != num2.length()) {
denom2 += num2.charAt(place2);
place2++;
}
}
// All those string variables with the values are converted into integers to be used in calculations.
int wholenum = Integer.parseInt(whole);
int wholenum2 = Integer.parseInt(whole2);
int numerator1 = Integer.parseInt(numer);
int denominator1 = Integer.parseInt(denom);
int numerator2 = Integer.parseInt(numer2);
int denominator2 = Integer.parseInt(denom2);
// Calculates the whole number into the fraction to get rid of any mixed numbers.
int wholenumerator1 = ((wholenum * denominator1) + numerator1);
int wholenumerator2 = ((wholenum2 * denominator2) + numerator2);
if(op.equals(plus)) { // If the operator is addition
ansnum = ((wholenumerator1 * denominator2) + (denominator1 * wholenumerator2)); // Cross multiply to get the numerator.
ansden = (denominator1 * denominator2); // Multiply both denominators to get a common denominator.
input1 = (ansnum + "/" + ansden);
System.out.println(input1);
}
else if(op.equals("multiply")) { // If the operator is multiplication
ansnum = (wholenumerator1 * wholenumerator2); // multiples both numerators.
ansden = (denominator1 * denominator2); // multiplies both denominators
input1 = (ansnum + "/" + ansden);
System.out.println(input1);
}
else if(op.equals("division")) { // If the operator is division
ansnum = (wholenumerator1 * denominator2); // multiplies numerator1 by the reciprocal of fraction 2 (denominator2)
ansden = (denominator1 * wholenumerator2); // multiplies denominator 1 by numerator2.
input1 = (ansnum + "/" + ansden);
System.out.println(input1);
}
else if(op.equals("subtract")) {
ansnum = ((wholenumerator1 * denominator2) - (wholenumerator2 * denominator1)); // multiplies numerator1 by denominator 2 and numerator 2 by denominator 1
ansden = (denominator1 * denominator2); // multiples both denominators to find a common denominator
input1 = (ansnum + "/" + ansden);
System.out.println(input1);
}
}
return input1;
}
}
答案 0 :(得分：1)
提示：如果您正在使用Eclipse，请突出显示所有内容并按ctrl-i以正确缩进代码。你会看到你的错误。
此外，不要将repeat == 1作为条件，然后切换repeat = 2，只需使用带有break语句的无限while循环。
答案 1 :(得分：0)
你走了，
import java.util.Scanner;
public class FracCalc {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int repeat = 1;
while (repeat == 1) {
System.out.println("Input your equation");
String equation = input.nextLine(); // Takes the user input and sets it equal to a variable (equation)
if (equation.equals("quit")) { // If the user inputs 'quit'
System.out.println("You've quit out of the calculator.");
repeat = 2; // repeat is set to 2 so the program can no longer run and it terminates.
} else {
System.out.println("Your answer is: " + produceAnswer(equation));//EDIT
}
}
}
public static String produceAnswer(String input) {
Scanner fraction = new Scanner(input);
String num1 = fraction.next().trim();
String op = fraction.next().trim();
String num2 = fraction.next().trim();
// Creates an empty string for each necessary variable for values to be added to them later on.
String plus = "+";
String multiply = "*";
String division = "/";
String subtract = "-";
String whole = "";
String numer = "";
String denom = "";
String whole2 = "";
String numer2 = "";
String denom2 = "";
// Creates variables ansnum and ansden to be manipulated later on in the calculations.
int ansnum = 0;
int ansden = 0;
// Creates place and place2 to act as counters to go through each token of the original equation input.
int place = 0;
int place2 = 0;
String input1 = ""; // Sets an empty string variable for the return.
if (num1.contains("_")) { // If the first fraction contains an _
while (num1.charAt(place) != '_') { // while the place (index) isn't equal to that _
whole += num1.charAt(place); // Set everything before it, equal to whole.
place++; // Each time increase the place (index) by 1.
}
place++; // Increases the place by 1 to pass the _ and move onto the next part of the fraction
}//EDIT
if (num1.contains("/")) { // If the first fraction contains a forward slash
while (num1.charAt(place) != '/') { // While the place does not equal its index
numer += num1.charAt(place); // Add every thing before it to a variable called numer
place++; // Each time increases the place (index) by 1.
}
place++; // Increases the place by 1 to pass the / and move onto the denominator.
}//EDIT
while (place != num1.length()) { // While the place (index) is less than the length of fraction 1
denom += num1.charAt(place); // Add every thing before it equal to the denom variable.
place++; // Each time increases the place (index) by 1.
}
place++;
// Same process as above is repeated for fraction 2.
if (num2.contains("_")) {
while (num2.charAt(place2) != '_') {
whole2 += num2.charAt(place2);
place2++;
}
place2++;
}//EDIT
if (num2.contains("/")) {
while (num2.charAt(place2) != '/') {
numer2 += num2.charAt(place2);
place2++;
}
place2++;
}//EDIT
while (place2 != num2.length()) {
denom2 += num2.charAt(place2);
place2++;
}
// All those string variables with the values are converted into integers to be used in calculations.
int wholenum = (whole.equals("")) ? 0 : Integer.parseInt(whole);//EDIT
int wholenum2 = (whole2.equals("")) ? 0 : Integer.parseInt(whole2);//EDIT
int numerator1 = Integer.parseInt(numer);
int denominator1 = Integer.parseInt(denom);
int numerator2 = Integer.parseInt(numer2);
int denominator2 = Integer.parseInt(denom2);
// Calculates the whole number into the fraction to get rid of any mixed numbers.
int wholenumerator1 = ((wholenum * denominator1) + numerator1);
int wholenumerator2 = ((wholenum2 * denominator2) + numerator2);
if (op.equals(plus)) { // If the operator is addition
ansnum = ((wholenumerator1 * denominator2) + (denominator1 * wholenumerator2)); // Cross multiply to get the numerator.
ansden = (denominator1 * denominator2); // Multiply both denominators to get a common denominator.
} else if (op.equals(multiply)) { // If the operator is multiplication
ansnum = (wholenumerator1 * wholenumerator2); // multiples both numerators.
ansden = (denominator1 * denominator2); // multiplies both denominators
} else if (op.equals(division)) { // If the operator is division
ansnum = (wholenumerator1 * denominator2); // multiplies numerator1 by the reciprocal of fraction 2 (denominator2)
ansden = (denominator1 * wholenumerator2); // multiplies denominator 1 by numerator2.
} else if (op.equals(subtract)) {
ansnum = ((wholenumerator1 * denominator2) - (wholenumerator2 * denominator1)); // multiplies numerator1 by denominator 2 and numerator 2 by denominator 1
ansden = (denominator1 * denominator2); // multiples both denominators to find a common denominator
}
input1 = (ansnum + "/" + ansden);//EDIT
return input1;
}
}
我已将更改标记为“// EDIT”。
如果有效，请将其标记为解决方案。