declare array with a default value?

[james]

Hi,

Just looking here: http://msdn2.microsoft.com/en-us/library/9b9dty7d.aspx I
can't quite see what I want to do.
I want an array of Booleans of length 102, all initially "false".
I have this so far:

public bool[] Monitors = new bool[102];

but if I add on the end of that : {false}, I get a compile error of "Invalid
rank specifier, expected ',' or ']'.
Now, I presume there is a quicker way than typing
{false,false,false,false.... 100 times?
Or does it default to false anyway?

 

[Guest]

Luckily for you, booleans are false by default anyway.

Ciaran O'Donnell

 

[coolCoder]

Hi,

Or does it default to false anyway?

You are right. When you initialize a new array of bool's all the
elements have default values set to False.


private void button1_Click(object sender, EventArgs e)
{

bool[] arr = new bool[3];


foreach (bool b in arr)
{
MessageBox.Show(b.ToString());
}


}

Try this code in a windows application for a button click event. You
can change the array size.

Thanks.

 

[james]

Hi,

Or does it default to false anyway?

You are right. When you initialize a new array of bool's all the
elements have default values set to False.


private void button1_Click(object sender, EventArgs e)
{

bool[] arr = new bool[3];


foreach (bool b in arr)
{
MessageBox.Show(b.ToString());
}


}

Try this code in a windows application for a button click event. You
can change the array size.

Thanks to both replies - false is handy
My other option was to simply loop through and set them all to false before
the *useful* stuff that will happen, but that seemed a horrible waste of cpu
cycles. A Default of false suits me fine.

James.

 

[Morten Wennevik]

Hi James,

All values types (int, bool etc) are set to their default level, which
usually is 0 or false. References will be null. If you want another
value you need to loop through and set it yourself.

Hi,

Or does it default to false anyway?

You are right. When you initialize a new array of bool's all the
elements have default values set to False.


private void button1_Click(object sender, EventArgs e)
{

bool[] arr = new bool[3];


foreach (bool b in arr)
{
MessageBox.Show(b.ToString());
}


}

Try this code in a windows application for a button click event. You
can change the array size.

Thanks to both replies - false is handy
My other option was to simply loop through and set them all to false
before
the *useful* stuff that will happen, but that seemed a horrible waste of
cpu
cycles. A Default of false suits me fine.

James.

 

[Noah Sham]

Hi,

In general, if you wanted to initialize your array of value types to a
specific value other than the default you would need to loop through the
array.

for (int x=0; x<Monitors.Length; ++x )
{
Monitors[x] = true;
}

 

[Bill Butler]

Hi,

Just looking here:
http://msdn2.microsoft.com/en-us/library/9b9dty7d.aspx I can't quite
see what I want to do.
I want an array of Booleans of length 102, all initially "false".
I have this so far:

public bool[] Monitors = new bool[102];

Have you looked into using the BitArray class instead of an Array of
bits?

Bill

 

[james]

Have you looked into using the BitArray class instead of an Array of bits?

I haven't - but I'll investigate. Presumably it's more efficient?

 

[Bill Butler]

I haven't - but I'll investigate. Presumably it's more efficient?

forgetting about overhead, an Array of bools takes up a whole byte for
every bit stored. It also has some constructors that ease
initialization.There are other features surrounding bit twiddling as
well.

Bill