قراردادهای والدین را می توان مستقیماً یا با استفاده از کلمه کلیدی فراخوانی کرد فوق العاده
.
با استفاده از کلمه کلیدی فوق العاده
، تمام قراردادهای مادر فوری فراخوانی می شود.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/* Inheritance tree
A
/ \
B C
\ /
D
*/
contract A {
// This is called an event. You can emit events from your function
// and they are logged into the transaction log.
// In our case, this will be useful for tracing function calls.
event Log(string message);
function foo() public virtual {
emit Log("A.foo called");
}
function bar() public virtual {
emit Log("A.bar called");
}
}
contract B is A {
function foo() public virtual override {
emit Log("B.foo called");
A.foo();
}
function bar() public virtual override {
emit Log("B.bar called");
super.bar();
}
}
contract C is A {
function foo() public virtual override {
emit Log("C.foo called");
A.foo();
}
function bar() public virtual override {
emit Log("C.bar called");
super.bar();
}
}
contract D is B, C {
// Try:
// - Call D.foo and check the transaction logs.
// Although D inherits A, B and C, it only called C and then A.
// - Call D.bar and check the transaction logs
// D called C, then B, and finally A.
// Although super was called twice (by B and C) it only called A once.
function foo() public override(B, C) {
super.foo();
}
function bar() public override(B, C) {
super.bar();
}
}