void methods
Learn void methods that do not return a value.
void methods
The void return type means the method returns no value. Such methods perform a side effect: they print to the screen, change state, or write to a file. They give nothing back.
Example: static void PrintLine(string text) { Console.WriteLine(text); }. This method takes a string and prints it to the screen; there is nothing to return to the caller.
void and return
The body of a void method has no return statement. Still, you can exit early with return; (no value). It is used to end the method immediately when a condition is met.
You cannot use a method that returns nothing in an assignment: int x = PrintLine("hello"); gives a compile error. Because void is not a value.
Exercise Print method
Define a static void PrintLine(string text) method; in the body call Console.WriteLine(text). In Main, call it with PrintLine("Hello").
Show example solution
Add Console.WriteLine(text); to the PrintLine body, write PrintLine("Hello"); in Main.
Example solution:
using System;
class Program
{
static void PrintLine(string text)
{
// Print text
Console.WriteLine(text);
}
static void Main()
{
// Call PrintLine with "Hello"
PrintLine("Hello");
}
}Test yourself
-
void method body
static void PrintLine(string text) { ____ }Show answer
static void PrintLine(string text) { Console.WriteLine(text); } -
Match each expression to its meaning
- void
- No value
- return 5;
- Returns 5
- Console.WriteLine
- Side effect
- static
- Class-level
-
What does the SayHi() call print?
static void SayHi() { Console.WriteLine("Hi"); } SayHi();- Hello
- Hi
- Hey
- void
Show answer
Hi — Correct. The SayHi body runs Console.WriteLine("Hi").