What is the difference between arrays and vectors in C++?
In C++, an array is a fixed-size data structure whose size needs to be specified at creation time, while a vector is a dynamic-sized data structure whose size can be changed at runtime. Arrays use the [] operator to access and modify elements, while vectors use the push_back() method to add elements and the [] operator to access elements. Arrays need to use delete[] to release memory, while vectors use erase() to delete elements.
Arrays and Vectors in C++: Differences and Practical Combat
In C++, arrays and vectors are used to store the same A collection of type data. However, they have some key differences in how they create, access, and manage data.
Array
An array is a fixed-size data structure whose size is specified when it is created. Use the [] operator to access and modify elements in an array.
int myArray[5] = {1, 2, 3, 4, 5};
cout << myArray[2]; // 输出 3
myArray[3] = 10; // 将元素 4 替换为 10Vector
A vector is a dynamically sized data structure whose size can change at runtime. Use the push_back() method to add elements and the [] operator to access and modify elements.
vector<int> myVector; // 创建一个空向量 myVector.push_back(1); myVector.push_back(2); myVector.push_back(3); cout << myVector[1]; // 输出 2 myVector[2] = 10; // 将元素 3 替换为 10
Difference
| Array | Vector | |
|---|---|---|
| Fixed | Dynamic | |
| Need to specify the size | No need Specify size | |
| Use myArray[index] | Use myVector.push_back() | |
| Use delete[] myArray; | Use myVector.erase() |
Calculate the average using an array
int main() {
int myArray[5] = {1, 2, 3, 4, 5};
int sum = 0;
for (int i = 0; i < 5; i++) {
sum += myArray[i];
}
double average = (double)sum / 5;
cout << average << endl;
return 0;
}Use a vector to store student scores
int main() {
vector<int> scores;
scores.push_back(85);
scores.push_back(90);
scores.push_back(95);
for (vector<int>::iterator it = scores.begin(); it != scores.end(); it++) {
cout << *it << endl;
}
return 0;
}The above is the detailed content of What is the difference between arrays and vectors in C++?. For more information, please follow other related articles on the PHP Chinese website!
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