The APLine problem from the 2010 AP Computer Science Exam is unusually easy. The problem requires you to write a simple class in response to a prompt that contains client code.
Review the APLine free response problem with AP CS Tutor Brandon Horn.
APLine
public class APLine
{
private int a, b, c;
public APLine(int a, int b, int c)
{
this.a = a;
this.b = b;
this.c = c;
}
public double getSlope()
{
return -(a / ((double) b));
}
public boolean isOnLine(int x, int y)
{
return a * x + b * y + c == 0;
}
}
2010 AP CS Exam Free Response Solutions |
Recommended Practice Problems |
what is the this. for ?
The instance fields have the same names as the parameters to the constructor.
this.arefers to the instance field.arefers to the parameter.this.a = aassigns the value of the parameter to the instance field.Another one . When you casted (double) to the slope , why did you just cast it to b ?
Thanks in advance .
When both operands are integers the
/operator performs integer division. When either operand is a double the operator performs double division.