Cheaper Gas v2

contracts/FundMe.sol

@@ -41,12 +41,12 @@ contract FundMe {
     /***** 6.1 Type Declarations *****/
     using PriceConverter for uint256;
     uint256 public constant MINIMUM_USD = 50 * 1e18;
-    address[] public s_funders;
-    address public immutable i_owner; // immutable only can declare 1 time at contructor
-    AggregatorV3Interface public s_priceFeed;
+    address[] private s_funders;
+    address private immutable i_owner; // immutable only can declare 1 time at contructor
+    AggregatorV3Interface private s_priceFeed;
 
     /***** 6.2 State Variable *****/
-    mapping(address => uint256) public s_addressToAmountFunded;
+    mapping(address => uint256) private s_addressToAmountFunded;
 
     /***** 6.3 Modifier *****/
     modifier onlyOwner() {
@@ -94,7 +94,7 @@ contract FundMe {
         require(
             msg.value.getConversionRate(s_priceFeed) >= MINIMUM_USD,
             "Didn't send enough"
-        );
+        ); // Use error code is gas cheaper
         s_funders.push(msg.sender);
         s_addressToAmountFunded[msg.sender] = msg.value;
     }
@@ -147,4 +147,23 @@ contract FundMe {
         (bool callSuccess, ) = i_owner.call{value: address(this).balance}("");
         require(callSuccess, "Call failed");
     }
+
+    // private variable is gas cheaper
+    function getOwner() public view returns (address) {
+        return i_owner;
+    }
+
+    function getFunders(uint256 index) public view returns (address) {
+        return s_funders[index];
+    }
+
+    function getAddressToAmountFunded(
+        address funder
+    ) public view returns (uint256) {
+        return s_addressToAmountFunded[funder];
+    }
+
+    function getPriceFeed() public view returns (AggregatorV3Interface) {
+        return s_priceFeed;
+    }
 }