problem solving assignment

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
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src/DateFormat.java

@@ -6,25 +6,29 @@ import java.util.TimeZone;
 
 public class DateFormat {
     public static void main(String[] args) {
-//        LocalDateTime d = LocalDateTime.now();
-//
-//
-////        Date Format1: Tue Aug 01 10:50:30 2017
-////        Date Format2: 2017 Aug 01 10:50:30
-//
-//        DateTimeFormatter df1 = DateTimeFormatter.ofPattern("E MMM dd HH:mm:ss yyyy");
-//        String fd1 = d.format(df1);
-//        System.out.println(fd1);
-//
-//        DateTimeFormatter df2 = DateTimeFormatter.ofPattern("yyyy MMM dd HH:mm:ss");
-//        String fd2 = d.format(df2);
-//        System.out.println(fd2);
-
-        // add days to date
-        LocalDateTime date = LocalDateTime.now().plusDays(-15);
-        DateTimeFormatter dateFormat = DateTimeFormatter.ofPattern("E MMM dd HH:mm:ss yyyy");
-        String dateString = date.format(dateFormat);
-        System.out.println(dateString);
+        LocalDateTime d = LocalDateTime.now();
+
+
+//        Date Format1: Tue Aug 01 10:50:30 2017
+//        Date Format2: 2017 Aug 01 10:50:30
+
+        DateTimeFormatter df1 = DateTimeFormatter.ofPattern("E MMM dd HH:mm:ss yyyy");
+        String fd1 = d.format(df1);
+        System.out.println(fd1);
+
+        DateTimeFormatter df2 = DateTimeFormatter.ofPattern("yyyy MMM dd HH:mm:ss");
+        String fd2 = d.format(df2);
+        System.out.println(fd2);
+
+        // add month to date
+        LocalDateTime myMonth = LocalDateTime.now().plusMonths(1);
+        DateTimeFormatter monthFormat = DateTimeFormatter.ofPattern("E MMM dd HH:mm:ss yyyy");
+        System.out.println("After adding 1 month: " + myMonth.format(monthFormat));
+
+        // subtract days to date
+        LocalDateTime myDay = LocalDateTime.now().plusDays(-15);
+        DateTimeFormatter dayFormat = DateTimeFormatter.ofPattern("E MMM dd HH:mm:ss yyyy");
+        System.out.println("After subtracting 15 days: " + myDay.format(dayFormat));
 
     }
 }

src/IsString.java

@@ -9,22 +9,33 @@ import java.util.regex.Pattern;
 
 public class IsString {
     public static void main(String[] args) {
-        String re = "-?\\d+(\\.\\d+)?";
         Scanner sc = new Scanner(System.in);
         System.out.println("Enter a valid string: ");
-        String myStr = sc.next();
-//        System.out.println(myStr);
-//        Pattern pattern = Pattern.compile("w3schools", Pattern.CASE_INSENSITIVE);
-//        Matcher matcher = pattern.matcher(myStr);
-//        boolean matchFound = matcher.find();
-        Pattern pt = Pattern.compile(re);
-        Matcher mt = pt.matcher(myStr);
-        boolean result = mt.matches();
-        if(myStr.contains("[0-9]+")) {
-            System.out.println("valid");
+        String myStr = sc.nextLine();
+
+        int status = 0;
+        int count = 0;
+        for (int i = 0; i < myStr.length(); i++) {
+            char c = myStr.charAt(i);
+            // regex for capital and small alphabets
+            if (Pattern.matches("[a-zA-z]", String.valueOf(c))) {
+            }
+            // regex for white space
+            else if(Pattern.matches("[\\s]", "" + c)){
+                count++;
+            }
+            else {
+                status = -1;
+                break;
+            }
+        }
+        if (count == myStr.length()) {
+            System.out.println("invalid");
+        }
+        else if (status == -1) {
+            System.out.println("invalid");
         } else {
-            System.out.println("not valid");
+            System.out.println("valid");
         }
     }
-}
-
+}
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