[Edit] C++: .size()

content/cpp/concepts/vectors/terms/size/size.md

@@ -1,19 +1,20 @@
 ---
 Title: '.size()'
-Description: 'Returns the number of elements in the vector.'
+Description: 'Returns the number of elements in a vector.'
 Subjects:
   - 'Computer Science'
   - 'Game Development'
 Tags:
-  - 'Vectors'
   - 'Arrays'
   - 'Data Structures'
+  - 'Elements'
+  - 'Vectors'
 CatalogContent:
   - 'learn-c-plus-plus'
   - 'paths/computer-science'
 ---
 
-The **`.size()`** method returns the number of elements in the vector. It follows the consistency of other standard library containers, such as [maps](https://www.codecademy.com/resources/docs/cpp/maps) and [strings](https://www.codecademy.com/resources/docs/cpp/strings).
+In C++, the **`.size()`** method returns the number of elements in the vector. This method is also available for other STL containers like `std::string`, `std::map`, and `std::list`. Knowing how to use `.size()` effectively helps in writing safe and efficient loops and conditionals.
 
 ## Syntax
 
@@ -23,25 +24,95 @@ vector.size();
 
 The `vector` must be defined using `std::vector` before the `.size()` method can be used.
 
-## Example
+**Parameters:**
+
+The `.size()` method does not accept any parameters.
+
+**Return value:**
+
+Returns the number of elements in a vector.
+
+## Example 1: Basic Usage
 
-In the example below, `.size()` is called on the `numbers` vector:
+In this example, `.size()` is called on the `numbers` vector:
 
 ```cpp
 #include <iostream>
 #include <vector>
 
 int main() {
-    // Declaring a vector with 4 integers
-    std::vector<int> numbers = {1, 2, 3, 4};
+  // Declaring a vector with 4 integers
+  std::vector<int> numbers = {1, 2, 3, 4};
 
-    // Print out vector size
-    std::cout << numbers.size();
+  // Print out vector size
+  std::cout << numbers.size();
 }
 ```
 
-The output of the above code is:
+Here is the output:
 
 ```shell
 4
 ```
+
+## Example 2: Using `.size()` in a Loop
+
+This example uses the `.size()` method in a `for` loop:
+
+```cpp
+#include <iostream>
+#include <vector>
+using namespace std;
+
+int main() {
+  vector<string> fruits = {"Apple", "Banana", "Cherry"};
+
+  for (size_t i = 0; i < fruits.size(); ++i) {
+    cout << fruits[i] << endl;
+  }
+
+  return 0;
+}
+```
+
+Here is the output:
+
+```shell
+Apple
+Banana
+Cherry
+```
+
+## Codebyte Example: Checking if a Vector is Empty
+
+In this codebyte example, `.size()` is used to determine if a vector is empty:
+
+```cpp
+#include <iostream>
+#include <vector>
+using namespace std;
+
+int main() {
+  vector<int> data;
+
+  if (data.size() == 0) {
+    cout << "The vector is empty." << endl;
+  }
+
+  return 0;
+}
+```
+
+## Frequently Asked Questions
+
+### 1. Can `.size()` be used with any STL container?
+
+Yes, `.size()` is a member function of most STL containers like `vector`, `string`, `list`, `map`, etc. It behaves similarly across them.
+
+### 2. What is the difference between `.size()` and `.capacity()`?
+
+`.size()` returns the actual number of items in a vector, whereas `.capacity()` returns the number of elements a vector can hold before needing to allocate more memory.
+
+### 3. Is `.size()` a costly operation?
+
+No, `.size()` runs in constant time, _O(1)_, because vectors store their size internally and update it automatically during insertions or deletions.