Finishing Up

5.7.4 Finishing Up

The last thing that the main method does before it exits is tell the user the results from the calculation. The two possible outcomes are either we found a root or we exceeded the allowed iterations. Again, we use an if construction, but this time we see also an addition, else.

We test to see if the last value of x qualifies as a root with:

	  if( Math.abs(f(x)) <= tolerance) {
	   System.out.println("Zero found at x="+x);
	  }
All of this should be clear from what you have seen earlier in the example. If we didn't find a root, we would like to tell the user this as well. We can tack on to the end of an if statement an else statement that will be executed if the if fails. In our case, this is:
	  else {
	   System.out.println("Failed to find a zero");
	  }
All together, then we have:
	  if( Math.abs(f(x)) <= tolerance) {
	   System.out.println("Zero found at x="+x);
	  }
	  else {
	   System.out.println("Failed to find a zero");
	  }

Notice that there is no return statement in main, since main returns type void.
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David Maxwell, who is still writing this, would like to hear your comments and suggestions.