未初始化向量的值< int> [英] C++ - value of uninitialized vector<int>

问题描述

我从这个问题，全局/静态未初始化的int的值将为0.对这一个说，对于向量，将调用对象类型的默认构造函数。

I understand from the answer to this question that values of global/static uninitialized int will be 0. The answer to this one says that for vectors, the default constructor for the object type will be called.

I我无法弄清楚 - 当我有向量< int> v（10）。 int 的默认构造函数是什么？如果我有向量< int> v（10）全局声明？

I am unable to figure out - what happens when I have vector<int> v(10) in a local function. What is the default constructor for int? What if I have vector<int> v(10) declared globally?

我看到的是 vector< int& v（10）在一个局部函数导致变量为0 - 但我不知道这是否只是因为我的编译器或是固定的预期行为。

What I am seeing is that vector<int> v(10) in a local function is resulting in variables being 0 - but I am not sure if that is just because of my compiler or is the fixed expected behaviour.

请注意，此行为与局部变量（例如 int x; ）不同，这会使值未初始化C语言，行为是继承自）。

Note that this behavior is different from a local variable such as int x; which leaves the value uninitialized (as in the C language that behavior is inherited from).

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