[問題] declaration of function in a function

[bjk (Up2u)]

請問在一個function裡面的declaration of function
是甚麼作用呢
謝謝

http://www.geeksforgeeks.org/output-of-c-program-set-5/

Question 3

#include<iostream>
using namespace std;

class Test
{
public:
  Test();
};

Test::Test()  {
    cout<<"Constructor Called \n";
}

int main()
{
    cout<<"Start \n";
    Test t1();
    cout<<"End \n";
    return 0;
}
Run on IDE
Output:
Start
End

Note that the line “Test t1();” is not a constructor call. Compiler
considers this line as declaration of function t1 that doesn’t recieve any
parameter and returns object of type Test.

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→ Caesar08: 跟extern一樣，讓function知道有別的function可以呼叫
→ bjk: 謝謝
→ tinlans: 這題看起來只是想考你那行是否等價於 Test t1;   XD
推 LPH66: 推樓上, 這是 C 留到 C++ 的一個非常容易令人搞錯的地方
→ LPH66: C++ 規定當這種東西看起來像宣告時它就是宣告
→ bjk: 謝謝各位大大XD