Xor

Intro to Solidity/contracts/fibonacci.sol

@@ -1,12 +1,26 @@
-pragma solidity 0.4.19;
-
-
-contract Fibonacci {
-    /* Carry out calculations to find the nth Fibonacci number */
-    function fibRecur(uint n) public pure returns (uint) {
+pragma solidity ^0.4.24;
+contract Fibbonacci {
+    uint a;
+    uint b;
+    uint c;
+    uint n;
+    uint i;
+    constructor () public{
+        a=0;
+        b=1;
+        i=1;
     }
-
-    /* Carry out calculations to find the nth Fibonacci number */
-    function fibIter(uint n) public returns (uint) {
+
+    function fiboIter(uint _n) public returns(uint){
+        n=_n;
+        for(i=1; i<n; i++){
+        c=a+b;
+        a=b;
+        b=c;
+        }
+        return c;
+    }
+    function print()public view returns(uint) {
+        return c;   
     }
 }

Intro to Solidity/contracts/greeter.sol

@@ -1,12 +1,11 @@
-pragma solidity 0.4.19;
-
+pragma solidity 0.4.24;
 
 contract Greeter {
     string private greeting;
-
-    function Greeter(string _greeter) public {
+    function Greeter() public {
+     greeting = "Hello World";
     }
-
-    function greet() public view returns (string) {
+    function greet()public view returns (string){
+        return greeting ;
     }
 }

Intro to Solidity/contracts/xor.sol

@@ -1,7 +1,15 @@
-pragma solidity 0.4.19;
-
-
-contract XOR {
-    function xor(uint a, uint b) public pure returns (uint) {
+
+pragma solidity 0.4.25;
+contract XOR{
+    uint c;
+    function xor (uint a,uint b) public view returns(uint) {
+        if(a == b) {
+            c = 0;
+            return c;
+        }
+        else {
+            c =1;
+            return c;
+        }
     }
 }