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This article mainly explains the "C++ standard library encapsulates vector array method", the content of the article is simple and clear, easy to learn and understand, now please follow the editor's train of thought slowly in depth, together to study and learn "C++ standard library encapsulation vector array method"!

Foreword:

If you build an array of basic types or an array of custom types, you need to extend the functionality of the array yourself, and there are many problems you need to solve, such as the need to prevent the array from crossing the bounds. At this point, you can use the vector template provided by the C++ standard library. The object created by vector contains many encapsulated functions, such as the "object name .size ()" function, which can easily view the size of the array. The following records are made in terms of definition, usage, and function references, and the differences between vector objects and arrays are discussed.

1. Create and use vector objects

The syntax for creating and using vector objects is as follows:

/ / create

Vector object name (array length, element initial value)

/ fetch elements

Object name [subscript]

/ / use the function of the object

Object name. Function name ()

The "type" you need to specify to create a vector object can be a basic data type or a class type, and if it is a basic data type, it can be initialized with a fixed value (the initial values of all elements can only be the same); if the "type" is a class type, the default constructor will be called for initialization. The first example below is an example of a basic data type as a vector element:

/ / build vector object, specify array length 3, initial value is 666vectordata (3666); / / fetch element printf ("% d\ n", data [1]); / / call function printf of vector object ("% d\ n", data.size ())

The second example is in the case of a class type, where the default constructor of the class is called to initialize:

/ / Custom Duck class class Duck {public: / / default constructor Duck () {duckAge = 666;} int duckAge;}; / / create a vector object of type Duck vectorducks (3); / / the element of vector is a Duck object, and the member printf ("% d\ n", ducks [1] .duckAge) of the Duck object can be called; 2. Reference to the vector object

Vector objects and other types of objects have the same rules for defining and using references, first declaring references, then pointing references to an object, and finally manipulating objects through references.

The following is the reference syntax for declaring vector types:

Vector & reference name

When using references as function parameters, it is best to define frequent references to prevent objects from being accidentally changed:

Void vectorSize (vector&vec) {printf ("% d\ n", vec.size ());} Thank you for reading, these are the contents of "the method of encapsulating vector array in C++ standard library". After the study of this article, I believe you have a deeper understanding of the method of encapsulating vector array in C++ standard library, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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