编写一个合约用于连接字符串

pragma solidity >=0.4.23; cotract JoinString{ function connectAtring(string a,string b) returns(string){ bytes _a=bytes(a) bytes _b=bytes(b)

    string connect=string(_a.length+_b.length)
    bytes _c=bytes(connect)
    for(uint i=0;i<=_a.length;i++){
        _c[i]=_a[i]
    }
    for(uint i=0;i<=_b.length;i++){
        _c[_b.length+i]=_b[i]
    }
    return string(_c)
}

}