LANG-1806: Allow floating-point suffixes in NumberUtils.isParsableDecimal

Author: Jagdish-Singh-Bisht

src/main/java/org/apache/commons/lang3/math/NumberUtils.java

@@ -753,8 +753,15 @@ private static boolean isParsableDecimal(final String str, final int beginIdx) {
         // See https://docs.oracle.com/javase/specs/jls/se8/html/jls-3.html#jls-NonZeroDigit
         int decimalPoints = 0;
         boolean asciiNumeric = true;
+        final int lastIndex = str.length() - 1;
+
         for (int i = beginIdx; i < str.length(); i++) {
             final char ch = str.charAt(i);
+
+            if(i == lastIndex && (ch == 'f' || ch == 'F' || ch == 'd' || ch == 'D')){
+                return true;
+            }
+
             final boolean isDecimalPoint = ch == '.';
             if (isDecimalPoint) {
                 decimalPoints++;

src/test/java/org/apache/commons/lang3/math/NumberUtilsTest.java

@@ -1028,8 +1028,8 @@ void testIsParsable() {
         assertTrue(NumberUtils.isParsable("-018.2"));
         assertTrue(NumberUtils.isParsable("-.236"));
         assertTrue(NumberUtils.isParsable("2."));
-        // TODO assertTrue(NumberUtils.isParsable("2.f"));
-        // TODO assertTrue(NumberUtils.isParsable("2.d"));
+        assertTrue(NumberUtils.isParsable("2.f"));
+        assertTrue(NumberUtils.isParsable("2.d"));
     }
 
     /**