Question

I have created a small Java application to automatically test some expressions for a true/false condition.

I am getting two compiler errors in both jGRASP and with the javac command.

The code follows:

public class MathTest {     public static void main(String[] args) {          int x = 10;         int y = 20;         int z = 30;         String string1 = 'six';         String string2 = 'six';          if (x < 10 || x > 10)             System.out.print('True');         else             System.out.print('False');          if (z - y == x && Math.abs(y - z) == z)             System.out.print('True');         else             System.out.print('False');          if (x < 10 && x < 10)             System.out.print('True');         else             System.out.print('False');          if (string1.equals(string2))             System.out.print('True');         else             System.out.print('False');         if (x > y || y > x)             System.out.print('True');         else             System.out.print('False');          if (!(x < y + z) || !(x + 10 <= 20))             System.out.print('True');         else             System.out.print('False');          if (string1 == string2)             System.out.print('True');         else             System.out.print('False');      } } 

The error message is:

     MathTest.java:14: cannot find symbol     symbol  : method abs(int)     location: class Math     if(z - y == x && Math.abs(y - z) == z)                      ^     ./Math.java:13: cannot find symbol     symbol  : method abs(int)     location: class Math     if(z - y == x && Math.abs(y - z) == z)                      ^     2 errors 

What am I doing wrong?

In the unlikely event that my instructor or any administrator from Salt Lake Community College ever comes across this question, let me make my intentions clear. This question is posted in the greatest spirit of academic honesty. I ask this question to seek general advice and help in understanding the proper way to use the Java programming language. I in no way use the work of others and represent it as my own work. I use the answers provided here as a general aid in my understanding. I do all my own work and do not copy work provided by people answering my question.

Answer 1

If you want your program to use Java’s Math.abs (instead of an abs() method in the Math class you wrote), you can say:

if(z - y == x && java.lang.Math.abs(y - z) == z) 

…which isn’t very pretty. In general, try not to name your classes the same as the ones in java.lang (or java.anything, really).