feat: Add method for capitalize first letter of each word from string

JavaDsaWithTest/src/main/java/org/practice/dsa/strings/CapitalizeFirstChar.java

@@ -0,0 +1,33 @@
+package org.practice.dsa.strings;
+
+public class CapitalizeFirstChar {
+    public static void main(String[] args) {
+        System.out.println(capitalize("hello world"));
+        System.out.println(capitalizeEach("hello world"));
+    }
+
+    // only first letter of first word
+    public static String capitalize(String str) {
+        if (str.isEmpty()) {
+            return str;
+        }
+        return str.substring(0, 1).toUpperCase() + str.substring(1);
+    }
+
+    // first letter of all words
+    public static String capitalizeEach(String str) {
+        if (str.isEmpty()) {
+            return str;
+        }
+        String[] words = str.split(" ");
+        StringBuilder result = new StringBuilder();
+        for (String word: words) {
+            if (!word.isEmpty()) {
+                result.append(word.substring(0, 1).toUpperCase())
+                        .append(word.substring(1))
+                        .append(" ");
+            }
+        }
+        return result.toString().trim();
+    }
+}