How to change Truffle default solc version 0.5.8

@abcoathup
I have deployed Successfully :grinning:

Contract

pragma solidity ^0.5.8;

        /**
         * @title SafeMaths
         * @dev Math operations with safety checks that throw on error
         */

        library SafeMath {
            function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                uint256 c = a * b;
                assert(a == 0 || c / a == b);
                return c;
            }

            function div(uint256 a, uint256 b) internal pure returns (uint256) {
                // assert(b > 0); // Solidity automatically throws when dividing by 0
                uint256 c = a / b;
                // assert(a == b * c + a % b); // There is no case in which this doesn't hold
                return c;
            }

            function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                assert(b <= a);
                return a - b;
            }

            function add(uint256 a, uint256 b) internal pure returns (uint256) {
                uint256 c = a + b;
                assert(c >= a);
                return c;
            }
        }

        /**
         * Welcome to the Telegram chat https://devsolidity.io/
         */
        contract Token {
            uint256 public totalSupply;

            function balanceOf(address who) public view returns (uint256);
            function transfer(address to, uint256 value) public returns (bool);
            function allowance(address owner, address spender) public view returns (uint256);
            function transferFrom(address from, address to, uint256 value) public returns (bool);
            function approve(address spender, uint256 value) public returns (bool);

            event Transfer(address indexed from, address indexed to, uint256 value);
            event Approval(address indexed owner, address indexed spender, uint256 value);
        }

        contract StandardToken is Token {
            using SafeMath for uint256;
            mapping(address => mapping (address => uint256)) internal allowed;
            mapping(address => uint256) balances;

            /**
            * @dev transfer token for a specified address
            * @param _to The address to transfer to.
            * @param _value The amount to be transferred.
            */
            function transfer(address _to, uint256 _value) public returns (bool) {
                require(_to != address(0));
                require(balances[msg.sender] >= _value && balances[_to].add(_value) >= balances[_to]);

                balances[msg.sender] = balances[msg.sender].sub(_value);
                balances[_to] = balances[_to].add(_value);

                emit Transfer(msg.sender, _to, _value);
                return true;
            }

            /**
            * @dev Gets the balance of the specified address.
            * @param _owner The address to query the the balance of.
            * @return An uint256 representing the amount owned by the passed address.
            */
            function balanceOf(address _owner) public view returns (uint256 balance) {
                return balances[_owner];
            }


            /**
            * @dev Transfer tokens from one address to another
            * @param _from address The address which you want to send tokens from
            * @param _to address The address which you want to transfer to
            * @param _value uint256 the amount of tokens to be transferred
            */
            function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
                require(_to != address(0));
                require(_value <= allowed[_from][msg.sender]);

                balances[_from] = balances[_from].sub(_value);
                balances[_to] = balances[_to].add(_value);
                allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);

                emit Transfer(_from, _to, _value);
                return true;
            }

            /**
            * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
            *
            * Beware that changing an allowance with this method brings the risk that someone may use both the old
            * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
            * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
            * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
            * @param _spender The address which will spend the funds.
            * @param _value The amount of tokens to be spent.
            */
            function approve(address _spender, uint256 _value) public returns (bool) {
                allowed[msg.sender][_spender] = _value;

                emit Approval(msg.sender, _spender, _value);
                return true;
            }

            /**
            * @dev Function to check the amount of tokens that an owner allowed to a spender.
            * @param _owner address The address which owns the funds.
            * @param _spender address The address which will spend the funds.
            * @return A uint256 specifying the amount of tokens still available for the spender.
            */
            function allowance(address _owner, address _spender) public view returns (uint256 remaining) {
                return allowed[_owner][_spender];
            }

            /**
            * approve should be called when allowed[_spender] == 0. To increment
            * allowed value is better to use this function to avoid 2 calls (and wait until
            * the first transaction is mined)
            * From MonolithDAO Token.sol
            */
            function increaseApproval(address _spender, uint256 _addedValue) public returns (bool success) {
                allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);

                emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
                return true;
            }

            function decreaseApproval(address _spender, uint256 _subtractedValue) public returns (bool success) {
                uint256 oldValue = allowed[msg.sender][_spender];

                if (_subtractedValue > oldValue) {
                  allowed[msg.sender][_spender] = 0;
                } else {
                  allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
                }

                emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
                return true;
            }
        }

        contract RahamanGIG is StandardToken {
            string public constant name = "RahamanGIG";
            string public constant symbol = "RMGIG";
            uint256 public constant decimals = 18;
            uint256 public constant INITIAL_SUPPLY = 100000000000000000000;
            address public tokenWallet;

            constructor() public {
                totalSupply = INITIAL_SUPPLY;
                tokenWallet = msg.sender;
                balances[tokenWallet] = totalSupply;
            }
        }

But I can deploy only pragma solidity ^0.5.8; Others version is not compile successfully.
How to change Truffle default solc version 0.5.8 to others?

1 Like

Hi @Rahaman,

In truffle-config.js there is a compilers section where you can specify the version. In the example below I am using the latest 0.6 version.

See the Truffle documentation for details: https://www.trufflesuite.com/docs/truffle/reference/configuration#compiler-configuration

// truffle-config.js
...

  // Configure your compilers
  compilers: {
    solc: {
      version: "^0.6",    // Fetch exact version from solc-bin (default: truffle's version)
      // docker: true,        // Use "0.5.1" you've installed locally with docker (default: false)
      // settings: {          // See the solidity docs for advice about optimization and evmVersion
      //  optimizer: {
      //    enabled: false,
      //    runs: 200
      //  },
      //  evmVersion: "byzantium"
      // }
    }
  }

...
1 Like

Thanks :+1: !!! :revolving_hearts:

1 Like