Create Minimal token Exercise.sol

Minimal exercise

Minimal token Exercise.sol

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+// Contract for an unburnable token
+contract UnburnableToken {
+    string private salt = "value"; // A private string variable
+
+    // Mapping to track token balances of addresses
+    mapping(address => uint256) public balances;
+
+    uint256 public totalSupply; // Total supply of tokens
+    uint256 public totalClaimed; // Total number of tokens claimed
+    mapping(address => bool) private claimed; // Mapping to track whether an address has claimed tokens
+
+    // Custom errors
+    error TokensClaimed(); // Error for attempting to claim tokens again
+    error AllTokensClaimed(); // Error for attempting to claim tokens when all are already claimed
+    error UnsafeTransfer(address _to); // Error for unsafe token transfer
+
+    // Constructor to set the total supply of tokens
+    constructor() {
+        totalSupply = 100000000; // Set the total supply of tokens
+    }
+
+    // Public function to claim tokens
+    function claim() public {
+        // Check if all tokens have been claimed
+        if (totalClaimed >= totalSupply) revert AllTokensClaimed();
+
+        // Check if the caller has already claimed tokens
+        if (claimed[msg.sender]) revert TokensClaimed();
+
+        // Update balances and claimed status
+        balances[msg.sender] += 1000;
+        totalClaimed += 1000;
+        claimed[msg.sender] = true;
+    }
+
+    // Public function for safe token transfer
+    function safeTransfer(address _to, uint256 _amount) public {
+        // Check for unsafe transfer conditions, including if the target address has a non-zero ether balance
+        if (_to == address(0) || _to.balance == 0) revert UnsafeTransfer(_to);
+
+        // Ensure the sender has enough balance to transfer
+        require(balances[msg.sender] >= _amount, "Insufficient balance");
+
+        // Perform the transfer
+        balances[msg.sender] -= _amount;
+        balances[_to] += _amount;
+    }
+}