Visual Basic: Evaluating Expressions
Introduction
Most programmers probably already know this, but for beginner programmers, it is quite frequently unknown or overlooked.
When you evaluate expressions you need not evaluate "If <expression> = true then", you simply evaluate "If <expression> then"
This is because <expression> already produces a Boolean value, and an if then branch breaks down to the following logic:
1.If <Expression> then
2. 'True was the case
3.Else
4. 'False was the case
5.End If
So when you evaluate the following expression for example:
(1+2 = 4)
This will automatically become false, because 1+2 does not equal 4.
True will always = true (It is what it is!)
False will always = false(It is what it is!)
Which means that saying:
1.If (1+2=4) = true then
2. 'True was the case
3.Else
4. 'False was the case
5.End If
is effectively saying the same as saying
1.If <Boolean> = true then
2.2. 'True was the case
3.3.Else
4.4. 'False was the case
5.5.End If
But since a Boolean "is what is", we need not check if "<Boolean>" = true...
So the following is the same as above:
1.If <Boolean> then
2. 'True was the case
3.Else
4. 'False was the case
5.End If
And the following is just as absurd as evaluating true in an expression:
1.If (((((1 + 2) = 3) = True) = True) = True) Then
2. 'True was the case
3.Else
4. 'False was the case
5.End If
In conclusion, try to remember, "It is what it is."
References
- MSDN Library http://msdn.microsoft.com/en-us/
- MSDN Forums http://social.msdn.microsoft.com/Forums/en-US/categories