How to use void in c++

The void type in C is a special data type that means the function does not return any value. Its main uses include: declaring functions that do not return any value. As a function parameter, it means that the function does not require any input. As a pointer type, it means that the pointer does not point to any specific object.

The void type in C

What is the void type?

void is a special data type in C, which means that the function does not return any value.

Uses of void

The void type is mainly used in the following scenarios:

• Declare a function that does not return any value:

<code class="cpp">void print_hello() {
  std::cout << "Hello, world!" << std::endl;
}</code>

• as a function parameter, indicating that the function does not require any input:

<code class="cpp">void swap(int& a, int& b) {
  int temp = a;
  a = b;
  b = temp;
}</code>

• as a pointer Type, indicating that the pointer does not point to any specific object:

<code class="cpp">void* ptr = nullptr;</code>

The difference between a void function and a function with a return type of int

void function and The main difference between functions with return type int is:

• Return value: void function does not return any value, while int function returns an integer.
• Calling method: void function is called directly, while int function needs to store the return value in a variable.

Example

The following example demonstrates the use of void type:

<code class="cpp">void print_number(int n) {
  std::cout << "The number is: " << n << std::endl;
}

int main() {
  print_number(42);
  return 0;
}</code>

Output:

<code>The number is: 42</code>

In this example , the print_number function is declared as void type, which means it does not return any value. However, it can accept an integer argument and print that integer.

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