Do you know “How to Initialize Vector Cpp“? Have you ever thought what is the process to initialize Vector Cpp? C++ is an important language to learn if you want to have a successful career in the programming field. Initializing a vector in C++ is one of the important concepts. Let us gain some knowledge about the process and ways to initialize it.
Still, if you have any issues while solving your C++ assignment then you can get C++ assignment help online by hiring the proficient experts at CodingZap.
We will first move with the basic definition of C++ Vector along with its basic declaration process. After clearing your basic foundation in Vector in C++, we will move ahead to the different initialization processes for C++ Vectors.
What Is A Vector? Get To Know
Vector in CPP programming language is different from the Vector concept in Physics or Biology. Vector is a special component that helps to store data in itself. It can only able to store similar kinds of data to it. This means all the integers or the value of the character can be stored in one single vector.
It seems like the Array. But this is different from the array in some mean. It only differs from the size perspective. The size of the array can’t be changed. Once it is declared, it will be fixed. However, the size of the vector can be changed. Sometimes a large number of data can be stored there.
Many other definitions are important to know while learning C++, one of them in Memory Leaks. So, if you want to know about this then you can read our article here.
In the C programming language, we used dynamic programming to store such types of data. We called them Dynamic Memory Allocation. Here, instead of that, we are using vectors for the same purpose. For getting a large number of the same kind of data, we need to initialize Vector Cpp.
If you’re curious to know about Dynamic Memory Allocation, then you can check out our article on “Dynamic Memory Allocation In C“
What Are The Basics Of Declaration Of Vector? Read Below
Now, after getting a simple definition of the C++ Vector, it is time to know its basic declaration process. It is the simple process by which we can use the C++ Vector in any program. But, before going for the declaration, we have to insert one main statement in the code.
For declaring a Vector in C++, we have to first include one header file. This header file will help to use the Vector & other methods associated with the Vector in C++. This is the library header file. After adding the header file we need to declare the vector.
The Header File: #include <vector>
For declaring the vector, we need to follow one specific syntax. First, we need to write a vector. Then inside the <> symbol, we need to write the nature of the data. This means we are going to add the integer value of the character value to the vector. Then we have to provide the name of it.
General Syntax: vector<data-type> name;
Simple Declaration of Vector in C++ Programming Language:
#include <vector>
Vector <int> v;
What Are The Methods To Initialize Vector? Read Below
There are a lot of methods present to initialize vector Cpp. Some of them can be assumed as the repetition of another method. But they are completely different from each other. Depending upon the use & importance, we can able to make a list of six methods. These methods can be used to initialize Vector Cpp.
- By Using Push_Back() Method
- By Using Size Of Vector
- By Using Array
- By Copying From Another Vector
- By Using The Index Of Vector
- By Using Fill() Method
Let us know about each & every method one by one briefly. But before that, we need to know the basic declaration of the Vector.
How To Initialize Vector Cpp By Using Push_Back() Method?
Push Back Method is the process by which we can insert any data to any blank C++ Vector. It is like the Insert operation we perform on any Lined List or Queue Data Structure. Here, the value will be shared as the Argument of Push back Method.
General Syntax: vectorname. push_back(value)
Program To Define The Push Back Method For Vector Using C++ Programming Language:
#include <iostream>
#include <vector>
using namespace std;
int main(){
vector<int> zap; // Create Empty Vector
// Adding Values One By One
zap.push_back(1);
zap.push_back(2);
for (int x : zap)
cout << x << " "; // Printing Values
return 0;}
Output:
From the above output, we can see that the two values Data 1 & Data 2 were successfully inserted in the program. And as the insertion operation was successful, the printing operation also succeeded.
How To Initialize Vector Cpp By Using Size Of Vector?
Here, we need to use the default size method of the Vector. We have to provide the size along with the value. This will help to add value that much times to it. In this way, we can able to add some data to Vector easily.
As the first argument, the size of the Vector should be provided. As the second argument, we have to provide the value that will be stored in the vector.
General Syntax: vector<data-type> vectorname(size, value);
Program To Define The Size Method For Vector Using C++ Programming Language:
#include <iostream>
#include <vector>
using namespace std;
int main(){
vector<int> zap(5, 2); // Vector Of Size 2 With All Values As 5
for (int x : zap)
cout << x << " "; // Printing Values
return 0;}
Steps Of The Program:
- Firstly, we have to define the header file by which we will use the Vector functions.
- Now, in the main function, the Size() Method will be used. We will provide Value 5 as the Size & Value 2 as the data.
- Now, one for loop will be implemented to print the stored value in the program.
Let us try to find out the output of the above code. This will help to know the process to initialize Vector Cpp.
Output:
From the above output, we can see that the declaration of the Vector has done completely well. The value 2 is inserted in the program five times, as the vector is declared with the size 5. Hence, the declaration of the Size() method has done errorless.
How To Initialize Vector Cpp By Using Array?
Here, the vector will be declared, but in a different format. The Array format will be used for initializing the Vector in C++. Hence, we can provide a series of data to the Vector without taking the help of the Push Back Method.
After declaring the data type, inside the braces, we have to provide the values that are separated with the comma. The Following Syntax can be used to refer to the declaration process.
General Syntax: vector<data-type> vectorname{value1, value2….};
Program To Define The Vector Using The Array Format In The CPP Language:
#include <iostream> #include <vector>
using namespace std;
int main(){
vector<int> zap{100, 200, 300}; // Initializing Like Array
for (int x : zap)
cout << x << " "; // Printing Values
return 0;}
Steps Of The Program:
- As with other Vector programs, we have to define the header file in the code.
- Now, according to the syntax we have to declare the array which will help to store values in the Vector in the sequential format.
- At last, we will print all the values in the Vector using the for loop concept.
Let us try to find out the output of the above code. This will help to know the process to initialize Vector Cpp.
Output:
From the above output, we can see that the printing process is completed successfully and the values can be seen in the output. So, the array that was declared for taking the values for the vector executed well.
How To Initialize Vector Cpp By Copying From Another Vector?
In this process, we will not declare any vector from scratch. Rather, we will copy one vector from another vector which is already declared & there are some values present. Luckily, the C++ Vector comes with an easy process to copy any other vector.
In that case, the vector where the data will get copied will be present outside of the braces. The Vector that is used for copying will be present between the braces. Do check the following syntax for getting more clarification.
General Syntax: vector<data-type> vectorname2(vectorname1);
Program To Implement The Process To Copy One Vector To Other In CPP:
#include <iostream> #include <vector>
using namespace std;
int main(){
vector<int> zap{11, 12, 13}; // Initializing Like Array
vector<int> codingzap(zap); // Copying Vector
for (int x : codingzap)
cout << x << " "; // Printing Values
return 0;}
Steps Of The Program:
- At first, the header file for the Vector should be imported into the program.
- Now, we will create any vector using the Array method which we have discussed earlier. It is the Zap Vector.
- Now, we will try to initialize another vector Codingzap by copying from the Zap. Using the syntax, we have operated.
- Now, using one loop, we will print the data of the Codingzap Vector.
Let us try to find out the output of the above code. This will help to know the process to initialize Vector Cpp.
Output:
Though, we have not inserted any values in the Vector. So, the Copying Operation from the Zap Vector has worked correctly.
How To Initialize Vector Cpp By Using Index Of Vector?
As there is a similarity between the Vector and Array, both have the same index values. This means, the Vector Data Structure also has Index values of the element & that is started from the Zero Value. We can use those Index Values to enter data into the Vector.
Just like the Arrays in the programming language, we have to use the Vector Indexes in the same format. You can go through the following program to clear the concept.
Program To Define The Index Values For Initializing Any Vector In CPP:
#include <iostream> #include <vector>
using namespace std;
void main(){
vector<int> zap(3); // Initializing Vector With Size
zap[0]=12; zap[1]=21; zap[2]=30; // Providing Value With Index
for (int x : zap)
cout << x << " ";} // Printing Values
Steps Of The Program:
- The first task is to insert the header file into the program for working with vectors.
- Now, we will declare one empty vector in the program with size three.
- Now, we will use the Index Values. For the 0 Index Value, we will insert 12 data there. For Index 1, the data 13 will be inserted & so on.
- Now, we will print the data using the for-loop concept.
Let us try to find out the output of the above code. This will help to know the process to initialize Vector Cpp.
Output:
From the above output, we can see that the values are getting printed in the program successfully. So, the insertion of values in the program was successful with the help of the index values. So, the program was declared correctly.
How To Initialize Vector Cpp By Using the Fill() Method?
The Fill() Method is another important method that works similarly to the Size() Method discussed earlier. In this case, also, a value gets stored repetitively in the vector until the end of the vector arrives. There are three arguments present in the Fill() Method.
The first one is the Begin() function, the second one is the End() Function & the third one is the value. We have to provide the Vector Name along with the Begin() & End() functions. We can follow the below syntax for more clarity.
General Syntax: fill(vectorname.begin(),vectorname.end(),value);
Program To Demonstrate The Use Of Fill() Method To Declare Vectors In CPP:
#include <iostream> #include <vector>
using namespace std;
int main(){
vector<int> zap(3); // Initializing Vector With Size
fill(zap.begin(),zap.end(),3); // Using Fill Method
for (int x : zap)
cout << x << " "; // Printing Values
return 0;}
Steps Of The Program:
- At first, the header file of the vector will be inserted in the code.
- Later, we will declare one empty vector with the size 3.
- Now, using the syntax, we will enter the value 3 in the vector.
- Now, we will define one For Loop for printing the values in the output.
Let us try to find out the output of the above code. This will help to know the process to initialize Vector Cpp.
Output:
From the above output, we can see that the value 3 is inserted in the program for 3 times. As the size of the vector is 3, the value will be inserted in the program 3 times. So, we have successfully used the Fill Method in the program.
What Are The Advantages & Disadvantages Of C++ Vectors?
At the end of our topic, we would like to conclude our discussion by explaining the advantages & disadvantages of C++ Vectors. The Advantages help to find out the reason to use Vectors in your challenging problems.
The Disadvantages will help you to save from potential issues after using the Vector in your program. So, you should be aware of both the positive & negative sides of the vector.
Advantages of C++ Vectors:
- Dynamic in nature which reduces the space wastage of the program.
- The data is stored continuously in the memory.
- Easy inbuilt functions to work smoothly on Vectors.
Disadvantages of C++ Vectors:
- As it is an object in OOPs the space consumption is much higher.
- The speed of execution is less than other Data Structure Elements.
- It is a Un-Synchronized Data Element.
Conclusion:
As we saw “How to Initialize Vector Cpp” is a very important topic.
We need to first clear the basics of the C++ programming language. This will help a lot to understand the topic in a better manner.
The Vector in C++ will help you a lot in the future. This is the key to removing the problems related to the space problem of data input. We have to practice it in a good manner.
Still having issues understanding, It is advisable to clear the basics of the C++ programming language, you can always hire a programming tutor from CodingZap. It will be easy for us to gain knowledge about this topic in an easy & proper manner.
So, hope you have liked this piece of article. Share your thoughts in the comments section and let us know if we can improve more.
