Trying to convert a bunch of C++ codes into Java - if statement

Question

i was trying to write some C++ codes into java, now i have writter following code into java but it is throwing errors!

if(ShapeNotFound && xd*yd - nPixel[k] < xd+yd)              // Condition for RECTANGLE
{

    System.out.print("\n      "+in+"  \t     Rectangle \n");
    fileWriter3.write("\n      "+in+"  \t     Rectangle \n");
    Shape[k] = 2;
    ShapeNotFound = 0;

}

I am getting following error :

The operator && is undefined for the argument type(s) int, boolean

Please help, tell me how to write the above if condition correctly in java

Answer 1

C and C++ both assume that for integers 0 is false and all other values are true.

Java does not make the same assumption so you need to add a check for int!=0 into the expression i.e.:

if((ShapeNotFound!=0) && (xd*yd - nPixel[k] < xd+yd))    

Or alternatively your ShapeNotFound variable should be of type boolean not int.

It would be worth converting variable names etc to Java style guidelines as well.

Answer 2

Java can not convert int into boolean automatically.

Answer 3

It looks like ShapeNotFound is an integer, but you're implicitly treating it like a boolean (true or false). Java only likes genuinely boolean expressions, so you'll need to change the condition to something like this:

if (ShapeNotFound != 0 && xd*yd - nPixel[k] < xd+yd)

For readability, I'd suggest putting some brackets round each part of the condition. That's an issue of personal preference though.