Using isDigit on args

Question

Hi am trying to use is digit on specific args to handle non numeric operands wilthout using exception handlers I have tried various ways but am having no luck and have not found any answers in the tutortials
most recent attempt as follows:
// Calculator.java: Pass parameters from the command line handle non numeric operands without exception handler
public class WithoutExHandler {
  /** Main method */
  public static void main(String[] args) {
    // Check command-line arguments
    if (args.length != 3) {
      System.out.println(
        "Usage: java Calculator operator operand1 operand2");
      System.exit(0);
  int result = 0;
     if (args[1].charAt(1).isDigit);
    if(args[2].charAt(2).isDitit);
    // Determine the operator
    switch (args[0].charAt(0)) {
      case '+': result = Integer.parseInt(args[1]) +
                         Integer.parseInt(args[2]);
                break;
      case '-': result = Integer.parseInt(args[1]) -
                         Integer.parseInt(args[2]);
                break;
      case '*': result = Integer.parseInt(args[1]) *
                         Integer.parseInt(args[2]);
                break;
      case '/': result = Integer.parseInt(args[1]) /
                         Integer.parseInt(args[2]);
    // Display result
    System.out.println(args[1] + ' ' + args[0] + ' ' + args[2]
      + " = " + result);
   // else {
    System.out.println("Wrong Input: " +  args[1] + ' ' + args[0] + ' ' + args[2]);
[\code]        
--------------------Configuration: tme4 - j2sdk1.4.1_06 <Default>--------------------
C:\Program Files\Xinox Software\JCreator LE\MyProjects\tme4\Exercise13_1WithoutExHandler.java:12: char cannot be dereferenced
     if (args[1].charAt(1).isDigit);
                ^
C:\Program Files\Xinox Software\JCreator LE\MyProjects\tme4\Exercise13_1WithoutExHandler.java:13: char cannot be dereferenced
    if(args[2].charAt(2).isDitit);
           ^
2 errors
Process completed.

Answer 1

lost it!! thought I had this working it compiles but when args are input at command line prompt I get
error in "main" string out of bounds exception: String index out of range 1
// Calculator.java: Pass parameters from the command line
import java.awt.*;
public class Exercise13_1WithoutExHandler2 {
  /** Main method */
  public static void main(String[] args) {
    // Check command-line arguments
    if (args.length != 3) {
      System.out.println(
        "Usage: java Calculator operator operand1 operand2");
      System.exit(0);
  int result = 0;
  if (Character.isDigit(args[1].charAt(1))) {
  if (Character.isDigit(args[2].charAt(2)))
    // Determine the operator
    switch (args[0].charAt(0)) {
      case '+': result = Integer.parseInt(args[1]) +
                         Integer.parseInt(args[2]);
                break;
      case '-': result = Integer.parseInt(args[1]) -
                         Integer.parseInt(args[2]);
                break;
      case '*': result = Integer.parseInt(args[1]) *
                         Integer.parseInt(args[2]);
                break;
      case '/': result = Integer.parseInt(args[1]) /
                         Integer.parseInt(args[2]);
    // Display result
    System.out.println(args[1] + ' ' + args[0] + ' ' + args[2]
      + " = " + result);
    else {
    System.out.println("Wrong Input: " +  args[1] + ' ' + args[0] + ' ' + args[2]);
   } }[\code]