while循环语句出现问题

Question

I keep getting errors when I try to compile these codes below, I'm currently using JCreator.

import java.io.*;

public class Number //class name here, same as file name

 {
 public Number()throws IOException{//constructor, place class name here
 // use BufferedReader class to input from the keyboard
 // declare a variable of type BufferedReader
 BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
 //declare variable for input
 String inputString;

int number;
int counter;
int square;
int cube;
String goodMessage = "Thank you";
String badMessage = "Sorry";

//begin houseKeeping()
System.out.print("Please input number: ");
inputString = input.readLine();
number = Integer.parseInt(inputString);

//begin squareCube()
counter = 0;
while ((counter = 0)&&(number > 0)) {
    square = number*number;
    cube = number*number*number;
    System.out.print(square);
    System.out.print(cube);
}
if (counter = counter + 1);
if (counter < 3);
System.out.print("Enter input number: ");

//begin finishUp()
if (number > 0)
    System.out.println(goodMessage);

    else 
    System.out.println(badMessage);

 }//end constructor

 public static void main(String [] args) throws IOException // main method

 {
 new Number(); //class constructor name
 } // end the main method
 } // end the program

Error:

--------------------Configuration: <Default>--------------------
D:\INFO\INFO 1391\Number.java:27: error: bad operand types for binary operator '&&'
    while ((counter = 0)&&(number > 0)) {
                        ^
  first type:  int
  second type: boolean
1 error

Process completed.

Answer 1

You can't use the = operator to compare values; that's the assignment operator. Use == to compare your int values:

while ((counter == 0)&&(number > 0)) {

The assignment operator here evaluates to an int , yielding the error message that you received.

Answer 2

counter = 0

应该

counter == 0

Answer 3

while ((counter = 0)&&(number > 0)) is never true, because (counter = 0) assigns counter to be 0 and the value of that statement is the value of counter : 0 . And 0 is int and can't be converted to boolean .

Answer 4

Where is the question?

There are so many errors in this code... To check if two integers are equal you have to write == not =. (In while and in if).