I would like to understand a part of the Ownable()
contract of the OpenZeppelin Solidity library:
modifier onlyOwner() {
require(isOwner());
_;
}
The last line of this modifier consists only of an underscore. Can anybody please explain to me or refer what the underscore does?
I checked other questions involving modifiers but could only find out that an underscore-command is an existential part of a modifier.
It's used to specify when the instructions in the modifier will be executed
If the instructions goes before _;
, then the code in the modifier will be executed before the function is executed.
modifier onlyOwner() {
require(isOwner());
_;
}
On the opposite, if the modifier is after _;
, then the instructions in the modifier will be executed after the function is executed.
modifier onlyOwner() {
_;
require(isOwner());
}
Source: https://www.educative.io/answers/what-is-in-solidity