Working on E1.java

Note that I will not necessarily attempt to fix all errors
at once. Instead, I will work on groups of errors at each
step, gradually whittling down the list. This is generally
a good strategy given that some errors might be really caused
by other errors: get rid of one error and others *might*
disappear.

I am using the Build Output tab at bottom of JCreator to get
more useful debugging info, i.e., a pointer into the line where
the compiler thinks the problem is.

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Error: V:\java-problems\solutions\E1.java:21: illegal start of expression
                        Value= digit* 2**exponent;
                                        ^
Cause: use of ** for exponentation.

Explanation: the compiler thought that the two *s were meant to be two separate multiplies.

Fix: changed to Math.pow( 2, exponent ).

=======================================================

Error: cannot resolve symbol variable <name> (multiple errors on lines 16,18,21,22).
       Choosing one:
       
        V:\java-problems\solutions\E1.java:16: cannot resolve symbol
	symbol  : variable exponet 
	location: class BinaryToDecimal
                exponet = 0;\
                ^
Cause: must declare the type of a variable before you use it.

Explanation: compiler was looking for something like "int exponent;" before this line.

Fix: add the type declarations for exponent, sum, value, digit.
     Renamed Value to value, digit to binary_digit, exponet to exponent.

=======================================================

Error: V:\java-problems\solutions\E1.java:17: cannot resolve symbol
	symbol  : method getnextdigit ()
	location: class BinaryToDecimal
                getnextdigit();
                ^
       This error appears on line 23 as well.
       
Cause: typo in method name: should be getNextDigit.

Explanation: case matters!

Fix: change to correct name.

=======================================================

Error: V:\java-problems\solutions\E1.java:21: possible loss of precision
	found   : double
	required: int
                        int value= binary_digit* Math.pow( 2, exponent);
                                               ^
                                               
Cause: int * double gives you a double. Then tried to pour the double into an int.

Explanation: need to cast to get compiler to accept this line.

Fix: cast results of Math.pow to int. Then have int * int and no problem.

=======================================================

Error: none at this point: compiles fine.

However, does not produce correct output. From this point, you
are stuck with what are called "logic" errors, i.e., errors
in your algorithm. The major problem is that getNextDigit is
called too many times. It should be used *once* in the loop.
Instead, it is used twice in the loop, and once before the
loop.

The other problem is that there is no output of the sum. This
should be placed after the loop has finished.