Will an IF statement stop evaluating if it fails the first condition?

c# if-statement conditional-statements
user1017882 picture user1017882 · Jul 6, 2012 · Viewed 48.1k times · Source

If I have an If statement with 2 conditions - and the first fails, will the 2nd condition even be considered or will it go straight to the else? So, in the following example, if myList.Count == 0, will myString be compared against "value" or will it just straight to else?

if(myList.Count > 0 && myString.Equals("value"))
{
//Do something
}
else
{
//Do something else
}

Answer

Paul Spangle picture Paul Spangle · Jul 6, 2012

It will stop evaluating because you're using the double ampersand && operator. This is called short-circuiting.

If you changed it to a single ampersand:

if(myList.Count > 0 & myString.Equals("value"))

it would evaluate both.

Related questions

Is "else if" faster than "switch() case"?

I'm an ex Pascal guy, currently learning C#. My question is the following: Is the code below faster than making a switch? int a = 5; if (a == 1) { .... } else if(a == 2) { .... } else if(a == 3) { .... } else if(a == 4) { .... } else .... And the switch: int …

Read More
One liner for If string is not null or empty else

I usually use something like this for various reasons throughout an application: if (String.IsNullOrEmpty(strFoo)) { FooTextBox.Text = "0"; } else { FooTextBox.Text = strFoo; } If I'm going to be using it a lot I will create a method that returns the desired …

Read More
Single line if statement with 2 actions

I'd like to do a single line if statement with more than 1 action. Default is this: (if) ? then : else userType = (user.Type == 0) ? "Admin" : "User"; But I don't need an "else" only, I need an "else if" like that in multi …

Read More