added strings in java

Author: GauravWalia19

C/README.md

@@ -52,6 +52,21 @@
   * DYNAMIC ARRAY
   * LINKED
 
+#### TREES
+
+* BINARY TREE
+* GENERIC TREES
+* THREADED BINARY TREE
+* XOR TREES
+* BINARY SEARCH TREE
+* AVL TREES
+* RED BLACK TREES
+* SPLAY TREES
+* AUGMENTED TREES
+* SCAPEGOAT TREES
+* INTERVAL TREES
+* HEAP TREE
+
 #### HEAPS
 
 * [1D ARRAYS USING HEAPS](Data-Structures/HEAPS/dynamicarray.c)

Java/Data-Structures/STRING/Strings.java

@@ -0,0 +1,51 @@
+public class Strings
+{
+    public static void main(String[] args) 
+    {   
+        /*USAGE OF STRING CLASS IN JAVA*/
+        String trial = "Hello World this is github";
+        
+        System.out.println("string:\t" + trial);
+        System.out.println();
+
+        System.out.println("METHODS IN STRING CLASS");
+        
+        //charAt()
+        System.out.println("charAt(3):\t\t\t" + trial.charAt(3));
+        
+        //indexOf()
+        System.out.println("indexOf('o'):\t\t\t" + trial.indexOf('o'));
+        System.out.println("indexOf('o',3):\t\t\t" + trial.indexOf('o',3));
+        System.out.println("indexOf(\"this\"):\t\t" + trial.indexOf("this"));
+        System.out.println("indexOf(\"this\",3):\t\t" + trial.indexOf("this",3));
+
+        //lastIndexOf()
+        System.out.println("lastIndexOf('o'):\t\t" + trial.lastIndexOf('o'));
+        System.out.println("lastIndexOf('o',3):\t\t" + trial.lastIndexOf('o',3));
+        System.out.println("lastIndexOf(\"this\"):\t\t" + trial.lastIndexOf("this"));
+        System.out.println("lastIndexOf(\"this\",4):\t\t" + trial.lastIndexOf("this",4));
+        
+        //length()
+        System.out.println("length():\t\t\t" + trial.length());
+        
+        //substring()
+        System.out.println("substring(1):\t\t\t" + trial.substring(1));
+        System.out.println("substring(3,5):\t\t\t" + trial.substring(3,5));
+        
+        //replace()
+        System.out.println("replace('a','b'):\t\t" + trial.replace('a','b'));
+        System.out.println("replace(\"Hello\",\"world\"):\t" + trial.replace("Hello","world"));
+        
+        //concat()
+        System.out.println("concat(\" Hello World\"):\t\t" + trial.concat(" Hello World"));
+        
+        //equals()
+        System.out.println("equals(\"Hello World this is github\"):\t" + trial.equals("hello wotld a bac a"));  
+        
+        //toUpperCase()
+        System.out.println("toUpperCase():\t\t\t" + trial.toUpperCase());
+
+        //toLowerCase()
+        System.out.println("toLowerCase():\t\t\t" + trial.toLowerCase());
+    }
+}

Java/README.md

@@ -13,6 +13,10 @@
 * [three dimensional array](Data-Structures/ARRAYS/threeDarray.java)
 * [four dimensional array](Data-Structures/ARRAYS/fourDarray.java)
 
+#### STRING
+
+* [implementation with methods](Data-Structures/STRING/Strings.java)
+
 #### LISTS
 
 * LINKED LIST
@@ -38,6 +42,10 @@
   * [Stack class](Data-Structures/STACKS/INBUILT-STACK/Stacks.java)
 * MISC STACKS
 
+#### QUEUES
+
+#### TREES
+
 ### :rocket: DYNAMIC PROGRAMMING
 
 ### :rocket: MISC

datastructures.md

@@ -63,6 +63,13 @@ Indexer for Data Structures Lover
 * implementation
   * [C](C/Data-Structures/ARRAYS/jaggedarray.c)
 
+### :octocat: STRING
+
+* blog
+* docs
+* implementation
+  * [JAVA](Java/Data-Structures/STRING/Strings.java)
+
 ### :octocat: LISTS
 
 #### SINGLE

docs/complexity.md

@@ -61,6 +61,8 @@ This page contains the complexities of different algorithms in this repository.
       * ARRAY CLASS IN C++
     * [MISC ARRAYS](#misc-arrays)
       * [JAGGED ARRAY](#jagged-array)
+  * [STRING](#string)
+    * [Strings in JAVA](#strings-in-java)
   * [LISTS](#lists)
     * SINGLE
       * [SINGULAR LINKED LIST](#singular-linked-list-having-head-and-next)
@@ -99,11 +101,23 @@ This page contains the complexities of different algorithms in this repository.
       * HEAPED PRIORITY QUEUE
   * HASHTABLE
   * TREES
+    * BINARY TREE
+    * GENERIC TREES
+    * THREADED BINARY TREE
+    * XOR TREES
+    * BINARY SEARCH TREE
+    * AVL TREES
+    * RED BLACK TREES
+    * SPLAY TREES
+    * AUGMENTED TREES
+    * SCAPEGOAT TREES
+    * INTERVAL TREES
+    * HEAP TREE
+  * GRAPHS
   * HEAPS
     * [DYNAMIC 1D ARRAY](#dynamic-1d-arrays-(CC++))
     * [DYNAMIC 2D ARRAY](#dynamic-2d-arrays-(CC++))
     * [DYNAMIC 3D ARRAY](#dynamic-3d-arrays-(CC++))
-  * GRAPHS
   * BLOCKCHAIN
 
 ## ALGORITHMS
@@ -122,7 +136,7 @@ This page contains the complexities of different algorithms in this repository.
 #### :rocket: SORTING
 
  SNo. | Algorithm | Order of complexity O(n) | Type of Complexity | Stable/Unstable Sort | In Place Algorithm | Space Complexity
- ---- | --------- | ------------------------ | ------------------ | -------------------- | ------------------ | ----------------
+ ---- | --------- Data-Structures/STRING/Strings.java| ------------------------ | ------------------ | -------------------- | ------------------ | ----------------
  1 | Bubble Sort | O(n^2) | Quadratic | Stable / Can be Unstable** | :heavy_check_mark: | O(1)
  2 | Selection Sort | O(n^2) | Quadratic | Unstable | :heavy_check_mark: | O(1)
  3 | Insertion Sort | O(n^2) | Quadratic | Stable | :heavy_check_mark: | O(1)
@@ -273,6 +287,22 @@ This page contains the complexities of different algorithms in this repository.
 
 ##### ARRAY CLASS IN C++
 
+### STRING
+
+#### Strings in JAVA
+
+SNo. | Methods | Order of complexity O(n) | Type of Complexity
+ 1 | char charAt() | O(1) | Constant
+ 2 | int indexOf() | O(n) | Linear
+ 3 | lastIndexOf() | O(n) | Linear
+ 4 | int length() | O(1) | Constant
+ 5 | substring() | O(n) | Linear
+ 6 | replace() | O(n) | Linear
+ 7 | concat(str) | O(n^2) | Quadratic
+ 8 | equals(str) | O(n) | Linear
+ 9 | toUpperCase() | O(n) | Linear
+ 10 | toLowerCase() | O(n) | Linear
+
 ### LISTS
 
 #### SINGLE