U++ 运营商 学习笔记

赋值：=该拷贝为深拷贝

TArray<int32> ValArr3;
ValArr3.Add(1);
ValArr3.Add(2);
ValArr3.Add(3);

auto ValArr4 = ValArr3;
// ValArr4 == [1,2,3];
ValArr4[0] = 5;
// ValArr3 == [1,2,3];
// ValArr4 == [5,2,3];

Append函数的代替方法operator+=：

ValArr4 += ValArr3;
// ValArr4 == [5,2,3,1,2,3]

MoveTemp：移动构造：是左值右值做区分所构成的产物，将一个对象直接全部给另一个对象，并销毁（师傅归西，把内力全部传给徒弟），时间复杂度为O(1)。

ValArr3 = MoveTemp(ValArr4);
// ValArr3 == [5,2,3,1,2,3]
// ValArr4 == []

  Operator==：做比较

TArray<FString> FlavorArr1;
FlavorArr1.Emplace(TEXT("Chocolate"));
FlavorArr1.Emplace(TEXT("Vanilla"));
// FlavorArr1 == ["Chocolate","Vanilla"]

auto FlavorArr2 = Str1Array;
// FlavorArr2 == ["Chocolate","Vanilla"]

bool bComparison1 = FlavorArr1 == FlavorArr2;
// bComparison1 == true

for (auto& Str : FlavorArr2)
{
    Str = Str.ToUpper();
}
// FlavorArr2 == ["CHOCOLATE","VANILLA"]

bool bComparison2 = FlavorArr1 == FlavorArr2;
// bComparison2 == true, because FString comparison ignores case

Exchange(FlavorArr2[0], FlavorArr2[1]);
// FlavorArr2 == ["VANILLA","CHOCOLATE"]

bool bComparison3 = FlavorArr1 == FlavorArr2;
// bComparison3 == false, because the order has changed