Data commit

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

@@ -0,0 +1 @@
+Integer.parseInt("12345")

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

@@ -0,0 +1 @@
+Float.parseFloat("123.456")

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

@@ -0,0 +1,47 @@
+public static void main(String[] args) {
+    String value;
+    value = "1234567";
+    System.out.printf("%-10s %b%n", value, isInteger(value));
+    value = "12345abc";
+    System.out.printf("%-10s %b%n", value, isInteger(value));
+    value = "-123.456";
+    System.out.printf("%-10s %b%n", value, isFloatingPoint(value));
+    value = "-.456";
+    System.out.printf("%-10s %b%n", value, isFloatingPoint(value));
+    value = "123.";
+    System.out.printf("%-10s %b%n", value, isFloatingPoint(value));
+    value = "123.abc";
+    System.out.printf("%-10s %b%n", value, isFloatingPoint(value));
+}
+
+static boolean isInteger(String string) {
+    String digits = "0123456789";
+    for (char character : string.toCharArray()) {
+        if (!digits.contains(String.valueOf(character)))
+            return false;
+    }
+    return true;
+}
+
+static boolean isFloatingPoint(String string) {
+    /* at least one decimal-point */
+    int indexOf = string.indexOf('.');
+    if (indexOf == -1)
+        return false;
+    /* assure only 1 decimal-point */
+    if (indexOf != string.lastIndexOf('.'))
+        return false;
+    if (string.charAt(0) == '-' || string.charAt(0) == '+') {
+        string = string.substring(1);
+        indexOf--;
+    }
+    String integer = string.substring(0, indexOf);
+    if (!integer.isEmpty()) {
+        if (!isInteger(integer))
+            return false;
+    }
+    String decimal = string.substring(indexOf + 1);
+    if (!decimal.isEmpty())
+        return isInteger(decimal);
+    return true;
+}

Task/Determine-if-a-string-is-numeric/Java/determine-if-a-string-is-numeric-4.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-5.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-6.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-7.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-8.java

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