以太坊solidity编程常见错误(不定期更新)

1、报错:

Expected token Semicolon got 'eth_compileSolidity' funtion setFunder(uint _u,uint _amount){

解决:

funtion关键字错了,需要用function;

2、报错:

Variable is declared as a storage pointer. Use an explicit "storage" keyword to silence this warning. Funder f = funders[_u]; ^------^

解决:

Funder f,定义指针需要加关键字storage ;修改为Funder storage f = funders[_u];

3、报错:

Invoking events without "emit" prefix is deprecated. e("newFunder",_add,_amount); ^-------------------------^

解决:

调用事件需要在前面加上emit关键字,修改为emit e("newFunder",_add,_amount);

4、报错:

No visibility specified. Defaulting to "public". function newFunder(address _add,uint _amount) returns (uint){ ^ (Relevant source part starts here and spans across multiple lines).

解决:

定义函数必须加上public关键字,修改为function newFunder(address _add,uint _amount) public returns (uint){

5、报错:

"msg.gas" has been deprecated in favor of "gasleft()" uint public _gas = msg.gas; ^-----^

解决:msg.gas已经被gasleft()替换了。修改为uint public _gas = gasleft();

6、报错:

"throw" is deprecated in favour of "revert()", "require()" and "assert()". throw ;

解决:solidity已经不支持thorw了,需要使用require,用法require()

throw 写法:

if(msg.sender !=chairperson ||voters[_voter].voted ){

throw ;

}

require写法:

require(msg.sender !=chairperson ||voters[_voter].voted);

7、报错:

This declaration shadows an existing declaration. Voter delegate = voters[to]; ^------------^

解决:变量重复定义,变量名和函数名不能相同。

8、报错:

error: Function state mutability can be restricted to pure

解决:以前版本是可以不指定类型internal pure(外部不可调用),public pure(外部可调用)(如不指定表示函数为可变行,需要限制)

9、报错:

"sha3" has been deprecated in favour of "keccak256"
解决:sha3已经替换为keccak256

上一篇:shape和selector的结合


下一篇:h5