C++ .clear()

The .clear() method is used to remove all elements from a vector.

Syntax

vector.clear();

The vector must be defined using std::vector before the .clear() method can be used.

Example

In the example below, .clear() method is called on the numbers vector:

#include <iostream>
#include <vector>

int main() {
  // Declaring a vector with 4 integers
  std::vector<int> numbers = {1, 2, 3, 4};

  // Print out vector size before clear method is called
  std::cout << "Before: " << numbers.size()<<"\n";

  // Call the clear method on numbers vector
  numbers.clear();

  // Print out the size after clear method is called
  std::cout << "After: " << numbers.size()<<"\n";
}

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The output of the above code is:

Before: 4
After: 0

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