Java Coding Problems

44. Checking the index in the range from 0 to length

To begin with, let's have a simple scenario to highlight this problem. This scenario may materialize in the following simple class:

public class Function {  private final int x;  public Function(int x) {    this.x = x;  }  public int xMinusY(int y) {    return x - y;  }  public static int oneMinusY(int y) {    return 1 - y;  }}

Notice that the preceding snippet of code doesn't assume any range restrictions over x and y. Now, let's impose the following ranges (this is very common with mathematical functions):

• x must be between 0 (inclusive) and 11 (exclusive), so x belongs to [0, 11].
• In the xMinusY() method, y must be between 0 (inclusive) and x (exclusive), so y belongs to [0, x].
• In the oneMinusY() ...