new files

Task/Determine-if-a-string-is-numeric/Java/determine-if-a-string-is-numeric-1.java

@@ -0,0 +1,10 @@
+public boolean isNumeric(String input) {
+  try {
+    Integer.parseInt(input);
+    return true;
+  }
+  catch (NumberFormatException e) {
+    // s is not numeric
+    return false;
+  }
+}

Task/Determine-if-a-string-is-numeric/Java/determine-if-a-string-is-numeric-2.java

@@ -0,0 +1,10 @@
+private static final boolean isNumeric(final String s) {
+  if (s == null || s.isEmpty()) return false;
+  for (int x = 0; x < s.length(); x++) {
+    final char c = s.charAt(x);
+    if (x == 0 && (c == '-')) continue;  // negative
+    if ((c >= '0') && (c <= '9')) continue;  // 0 - 9
+    return false; // invalid
+  }
+  return true; // valid
+}

Task/Determine-if-a-string-is-numeric/Java/determine-if-a-string-is-numeric-3.java

@@ -0,0 +1,3 @@
+public static boolean isNumeric(String inputData) {
+  return inputData.matches("[-+]?\\d+(\\.\\d+)?");
+}

Task/Determine-if-a-string-is-numeric/Java/determine-if-a-string-is-numeric-4.java

@@ -0,0 +1,6 @@
+public static boolean isNumeric(String inputData) {
+  NumberFormat formatter = NumberFormat.getInstance();
+  ParsePosition pos = new ParsePosition(0);
+  formatter.parse(inputData, pos);
+  return inputData.length() == pos.getIndex();
+}

Task/Determine-if-a-string-is-numeric/Java/determine-if-a-string-is-numeric-5.java

@@ -0,0 +1,4 @@
+public static boolean isNumeric(String inputData) {
+  Scanner sc = new Scanner(inputData);
+  return sc.hasNextInt();
+}