#include<iostream>
using namespace std;
int init0;
int main()
{
//这2个都是c++11新支持的东东
int a = {3};//无警告!!!
int b{2};//extended initializer lists only available with -std=c++11 or -std=gnu++11 [默认启用]
cout << a << endl;
cout << b << endl;
long double c = 123.123456789;
//这一行代码居然只是警告!按书上说应该是个error啊
int d{c},e={c};//narrowing conversion of ‘c’ from ‘long double’ to ‘int’ inside { } is ill-formed in C++11 [-Wnarrowing]
cout << d << endl;
cout << e << endl;
int init1;
cout << "init0:" << init0 << endl;
cout << "init1:" << init1 << endl;
return 0;
}
3
2
123
123
init0:0
init1:134519912
一直觉得变量不初始化就是万恶之源,可为什么c++不给函数内的变量一个default value呢?