How to Get Length of a Vector in C++ - Step by Step Examples

How to Get Length of a Vector in C++ ?

Answer

To get the length of a vector in C++, you can use the size method of the std::vector class from the Standard Template Library (STL).


✐ Examples

1 Get Length of a Numeric Vector

In this example,

  1. We include the header to use the std::vector class and the header to use input/output streams.
  2. We create a vector named num_vector that holds integers using the std::vector declaration.
  3. We initialize num_vector with a set of numeric values using an initializer list {10, 20, 30, 40, 50}.
  4. We call the size method on num_vector to get the number of elements in the vector. The size method returns the length of the vector as a size_t value.
  5. We assign the result of the size method to a variable named num_vector_length.
  6. Finally, we print the length of the vector using std::cout to display the value of num_vector_length on the console.

C++ Program

#include <vector>
#include <iostream>

int main() {
    std::vector<int> num_vector = {10, 20, 30, 40, 50};
    std::size_t num_vector_length = num_vector.size();
    std::cout << "Length of numeric vector: " << num_vector_length << std::endl;
    return 0;
}

Output

Length of numeric vector: 5

2 Get Length of a String Vector

In this example,

  1. We include the header to use the std::vector class and the header to use input/output streams.
  2. We create a vector named str_vector that holds strings using the std::vector declaration.
  3. We initialize str_vector with a set of string values using an initializer list {"apple", "banana", "cherry"}.
  4. We call the size method on str_vector to get the number of elements in the vector. The size method returns the length of the vector as a size_t value.
  5. We assign the result of the size method to a variable named str_vector_length.
  6. Finally, we print the length of the vector using std::cout to display the value of str_vector_length on the console.

C++ Program

#include <vector>
#include <iostream>

int main() {
    std::vector<std::string> str_vector = {"apple", "banana", "cherry"};
    std::size_t str_vector_length = str_vector.size();
    std::cout << "Length of string vector: " << str_vector_length << std::endl;
    return 0;
}

Output

Length of string vector: 3

Summary

In this tutorial, we learned How to Get Length of a Vector in C++ language with well detailed examples.


More C++ Vectors Tutorials

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  2. How to Initialize a Vector in C++ ?
  3. How to Get Length of a Vector in C++ ?
  4. How to create a Vector of Size N in C++ ?
  5. How to create a Vector of Numbers from 1 to N in C++ ?
  6. How to create a Vector of Integers in C++ ?
  7. How to create a Vector of Strings in C++ ?
  8. How to create a Vector of Empty Vectors in C++ ?
  9. How to Access Items in a Vector in C++ ?
  10. How to get Item in a Vector at a Specific Index in C++ ?
  11. How to get First Item in a Vector in C++ ?
  12. How to get Last Item in a Vector in C++ ?
  13. How to Iterate Over a Vector in C++ ?
  14. How to Iterate Over a Vector with Index in C++ ?
  15. How to Iterate Over a Vector in Reverse Order in C++ ?
  16. How to check if a Vector is Empty in C++ ?
  17. How to check if a Vector is Not Empty in C++ ?
  18. How to get Sub Vector in C++ ?
  19. How to get the Index of Specified Item in a Vector in C++ ?
  20. How to check if a Specific Item is present in the Vector in C++ ?
  21. How to check if a Vector contains all the items of Another Vector in C++ ?
  22. How to count the Number of Occurrences of Specific Item in the Vector in C++ ?
  23. How to find the Item with Maximum Number of Occurrences in a Vector in C++ ?
  24. How to find the Item with Minimum Number of Occurrences in a Vector in C++ ?
  25. How to Sort a Vector in C++ ?
  26. How to Sort a Vector in Ascending Order in C++ ?
  27. How to Sort a Vector in Descending Order in C++ ?
  28. How to create a Two Dimensional Vector in C++ ?
  29. How to Iterate over a Two Dimensional Vector in C++ ?
  30. How to create a Three Dimensional Vector in C++ ?
  31. How to Copy a Vector in C++ ?
  32. How to Split a Vector in C++ ?
  33. How to Join Vectors in C++ ?
  34. How to Append an Item to a Vector in C++ ?
  35. How to Insert an Item at Specific Index in a Vector in C++ ?
  36. How to Append a Vector to another Vector in C++ ?
  37. How to Concatenate Two Vectors in C++ ?
  38. How to check if Two Vectors are Equal in C++ ?
  39. How to check if Two Vectors have Same Items (Regardless of Order) in C++ ?
  40. How to Convert a Vector of Integers to a Vector of Strings in C++ ?
  41. How to Convert a Vector of Strings to a Vector of Integers in C++ ?
  42. How to Convert a Vector of Floats to a Vector of Strings in C++ ?
  43. How to Convert a Vector of Strings to a Vector of Floats in C++ ?
  44. How to Reverse a Vector in C++ ?
  45. How to Shuffle a Vector in C++ ?
  46. How to Slice a Vector in C++ ?
  47. How to get First N Items from a Vector in C++ ?
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  50. How to Filter Items of a Vector based on a Condition in C++ ?
  51. How to Remove Duplicates in a Vector in C++ ?
  52. How to Remove Item at a Specific Index from a Vector in C++ ?
  53. How to Remove Specific Item from a Vector in C++ ?
  54. How to Remove Items from Vector based on a Condition in C++ ?
  55. How to Sort a String Vector in Dictionary Order in C++ ?
  56. How to Concatenate Strings in Vector in C++ ?
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