Name: C++ 中的矢量類型 (The Vector Type in C++)
Uploaded: 2025-05-27T13:43:12.000Z
Duration: 6 min 33 s

In this lecture, we will start discussing the vector type.

在本講座中，我們將開始討論向量類型。

關係子句

Now, vectors are sequence containers that represent variable size arrays.

現在，向量是表示大小可變數組的序列容器。

Remember these two terms, containers and variable size arrays.

請記住這兩個術語：容器和可變大小數組。

現在，讓我們來看看這些是什麼意思。

Containers actually means they contain other objects.

容器實際上是指它們包含其他對象。

So, vectors contain other objects and by variable size arrays, we mean that they are a collection of objects.

是以，矢量包含其他對象，而我們所說的可變大小數組是指它們是對象的集合。

So, they could be collection of other objects which can be of variable size.

是以，它們可以是其他對象的集合，這些對象的大小可以是可變的。

So, they are actually something that holds other objects.

是以，它們實際上是容納其他物體的東西。

Now, let's see how we make use of the vectors.

現在，讓我們看看如何使用矢量。

For using vectors, we have to include the appropriate headers.

要使用矢量，我們必須包含適當的標頭。

So, while using strings, we saw that we were including include string.

是以，在使用字符串時，我們發現我們包含了 include 字符串。

Similarly, for vectors, we have to include the header vector and then also we can make use of the standard library vector to make use of the vector based functions.

同樣，對於向量，我們必須包含頭文件向量，然後還可以使用標準庫向量來使用基於向量的函數。

Or if you are including the namespace std, that would be enough.

或者，如果你包含命名空間 std，這就足夠了。

But remember, this is the library that would contain all the vector type functions and things related to the vector.

但請記住，這個庫將包含所有向量類型的函數和與向量相關的內容。

Now, let's try to understand what we mean by class template.

現在，讓我們來理解一下類模板的含義。

A class template is a blueprint from which specific class types can be created.

類模板是一個藍圖，可以據此創建特定的類類型。

Try to understand the meaning of this from the name itself, which is class template.

試著從名稱本身（即類模板）來理解其含義。

Template means it is a blueprint and from this, we can create specific class types.

模板意味著它是一個藍圖，由此我們可以創建特定的類類型。

Okay, it will become clear as we move ahead.

好了，我們繼續前進就會明白了。

When we talk about template, remember that templates are not functions or classes, but they are guidelines for the compiler to use or create classes or functions.

當我們談論模板時，請記住模板不是函數或類，而是編譯器使用或創建類或函數的指南。

So, remember when we say a template, it is not a function or class by itself, but it is just a guideline or the blueprint which we use to create classes or functions.

是以，請記住，當我們說模板時，它本身並不是函數或類，而只是我們用來創建類或函數的指南或藍圖。

Now, the process that describes the procedure the compiler employs to build classes or functions out of templates is called instantiation.

現在，描述編譯器從模板中構建類或函數的過程稱為實例化。

Alright, so keep these prerequisites in mind as we discuss the vector type.

好了，在我們討論向量類型時，請記住這些前提條件。

We specify which class to instantiate by supplying additional information depending on the template.

我們根據模板提供附加資訊，指定要實例化哪個類。

Let's see what is this additional information that we need to supply.

讓我們看看我們需要提供哪些額外資訊。

在這裡，我們感興趣的是向量。

那麼，讓我們來看看是如何做到的。

We enclose it in two angle brackets after the template's name.

我們將其括在模板名稱後的兩個角括號中。

Since we are dealing with vectors, let's see how it is done for vectors.

既然我們處理的是矢量，那就讓我們來看看如何處理矢量。

For vectors, we specify the type of the objects that the vector will hold like this.

對於向量，我們可以像這樣指定向量所包含對象的類型。

We specify the keyword vector and within angle brackets, we specify the type that it is going to hold which is integer for this example and this is the name of the vector that is myVec.

我們指定關鍵字 vector（向量），並在角括號內指定它要保存的類型，本例中為整型，這就是向量的名稱 myVec。

Okay, seeing this example, I hope all these things now falls into place in your mind.

好了，看到這個例子，我希望所有這些事情現在都能在你的腦海中浮現出來。

Here, this vector is a template that we are trying to use and what is this template?

這裡，這個矢量是我們要使用的模板，這個模板是什麼呢？

It is going to be a collection of the integer type objects.

它將是一個整數類型對象的集合。

好吧，那我們如何具體說明呢？

We specify it by enclosing it in angle brackets after the template's name which is vector.

我們可以在模板名稱（即矢量）之後用角括號將其括起來。

Then, here we specify the name of the vector that we want to use.

然後，我們在這裡指定要使用的向量名稱。

Alright, so, let's take an example and see how this is used in a program and then the details of that we will discuss in the coming lectures.

好了，讓我們舉個例子，看看如何在程序中使用它，具體細節我們將在接下來的講座中討論。

So, in this example, here is a complete program that makes use of vectors.

是以，在這個例子中，這裡有一個使用向量的完整程序。

So, as you can see, we include the usual header that we have iostream and then it is very important to include the vector header.

是以，正如你所看到的，我們包含了 iostream 的常規標頭，然後包含矢量標頭也非常重要。

Don't forget this and you can also include the vector library namespace that I showed you or if you are just using namespace std, that would be enough.

不要忘記這一點，你也可以包含我向你展示的向量庫命名空間，或者如果你只是使用命名空間 std，這就足夠了。

And here in the main function, we are declaring that vector that I showed you in the example in the previous slide.

在主函數中，我們聲明瞭我在上一張幻燈片的示例中向你展示的向量。

So, it is a template that is going to hold integer type objects and then the name of the vector is myVec.

是以，這是一個用於保存整數類型對象的模板，向量的名稱是 myVec。

And in this myVec, I am storing these integer values 1, 2, 3, 4, 5.

在 myVec 中，我存儲了 1、2、3、4、5 這些整數值。

So, we see we have to put it in curly braces and each of the values are separated by comma.

是以，我們看到必須把它放在大括號中，每個值都用逗號隔開。

Okay, so, we see that this vector is holding integer values.

好了，我們看到這個向量保存的是整數值。

Now, you must be getting an idea of what are vectors.

現在，你一定對什麼是矢量有所瞭解了吧。

They are containers that are used for holding other objects.

它們是用來盛放其他物體的容器。

So, we see in this vector myVec, it is a container and it is holding these integer type objects.

是以，我們看到在這個向量 myVec 中，它是一個容器，容納了這些整數類型的對象。

Now, I hope the definition makes sense to you.

現在，我希望這個定義對你有意義。

Next, we would like to just print out these values.

接下來，我們要打印出這些值。

For that, I am making use of the range for statement.

為此，我使用了範圍 for 語句。

So, I say for and int i which is a variable that will be used for going over all these objects here and then after colon, I write the name of the vector which is myVec and then we are printing it out cout i and newline.

是以，我輸入 for 和 int i，這是一個變量，將用於遍歷這裡的所有對象，然後在冒號後面寫入向量的名稱，即 myVec，然後打印出來 cout i 和換行。

So, all these values should be printed on newlines.

是以，所有這些值都應打印在換行符上。

Okay, let's run this program in visual studio code and see if it is working.

好了，讓我們在 visual studio 代碼中運行這個程序，看看它是否正常工作。

Okay, so here we have the program called vec1.cpp, the same one that I showed you.

好了，現在我們有一個名為 vec1.cpp 的程序，就是我給你演示過的那個。

Okay, so as I compile and run it, you can see that these values 1, 2, 3, 4, 5, they are printed on newlines 1, 2, 3, 4, 5.

好的，當我編譯並運行它時，你可以看到這些值 1、2、3、4、5 被打印在換行符 1、2、3、4、5 上。

So, we have successfully defined a vector which is a container for holding integer objects in this example and then we have stored the integer values 1, 2, 3, 4, 5 and we have successfully printed it out.

是以，在這個示例中，我們成功定義了一個矢量，它是存放整數對象的容器，然後我們存儲了整數值 1、2、3、4、5，併成功將其打印出來。

And also remember, initially as we began this lecture, I told you that it can hold variable size arrays.

還記得嗎，一開始講課時，我告訴過大家，它可以容納大小可變的數組。

That means, the size of the objects can vary.

也就是說，物體的大小可能會有所不同。

So, here you see, I did not specify anywhere that I am going to store only five values here.

所以，在這裡你可以看到，我並沒有在任何地方指定只存儲五個值。

So, if I want, I can put more values like this or I can also reduce some of the values like this.

是以，如果我願意，可以像這樣輸入更多的值，或者像這樣減少一些值。

是以，我們看到大小是不同的。

It is dynamic and we don't have to specify anywhere that we are going to use a fixed size.

它是動態的，我們不必在任何地方指定使用固定大小。

With this example, I hope you have understood what are vectors and I hope all the definitions and all the lines that we saw in this lecture have now become clear by looking at this example.

通過這個例子，我希望你們已經明白了什麼是向量，也希望我們在本講座中看到的所有定義和所有線條都能通過這個例子變得清晰起來。

Alright, so that was just the introduction to vectors.

We will discuss more about its definition and how it is used and its various use cases in the coming lectures.

我們將在接下來的講座中進一步討論其定義、使用方法和各種用例。

So, I hope this introduction was clear to you.

所以，我希望這些介紹對你來說是清楚的。

Thank you for watching and see you in the next one.