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It's important to know that having a method print output using Console.WriteLine is not the same as having a method return a value.
It's important to know that having a method print output using Console.WriteLine
is not the same as having a method return a value. If you confuse the two, your programs are going to behave strangely, and you won't know why. So I wanted to spend this video clarifying the difference.
- Here's a version of our program with the
Subtract
method removed. - Suppose I remove the
return
statement from theAdd
method, and instead passed the result of adding the numbers toConsole.Writeline
:Console.WriteLine(first + second);
- I'll get an error: "'Program.Add(double, double)': not all code paths return a value"
static double Add(double first, double second)
{
Console.WriteLine(first + second);
}
- Converting the return type of
Add
tovoid
gets theAdd
method declaration to compile...- But then we get the error "Cannot implicitly convert type 'void' to 'double'" when the code down in
Main
expects a return value.
- But then we get the error "Cannot implicitly convert type 'void' to 'double'" when the code down in
static void Add(double first, double second)
{
Console.WriteLine(first + second);
}
static void Main(string[] args)
{
double total = Add(3, 5);
Console.WriteLine(total);
}
- Just remember, if you want your method to give information to a human, you can call
Console.WriteLine
. - But if you want your method to give information back to your program, you need to specify a return type and use the
return
keyword instead.
static double Add(double first, double second)
{
return first + second;
}
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