B4J Question B4J - Simple Question - Number of Objects

EnriqueGonzalez

Expert

Licensed User

Longtime User

• Aug 6, 2021

• #2

If you are using array ??

Dim arr(5) as button

Then use

Arr.length without parentheses

 

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AlexOfOz

Active Member

Licensed User

• Aug 6, 2021

• #3

Arr.length - Excellent. Thank-you very much.

I knew there would be a way; I just didn't know what it was.

Much appreciated

 

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Erel

B4X founder

Staff member

Licensed User

Longtime User

• Aug 6, 2021

• #4

Tips:
1. Prefer lists of arrays.
2. Prefer For Each over For i:

B4X:

For Each btn As B4XView In MyButtons
 ...
Next

 

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AlexOfOz

Active Member

Licensed User

• Aug 7, 2021

• #5

Thank-you Erel, I will try FOR EACH instead.

The root of my question was answered with ARR.LENGTH. I expected there would be a way, just like the LENGTH parm for a string, but it never occurred to me that it could be so straight forward.

I am now using this method throughout my program and it is working beautifully.

 

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amorosik

Expert

Licensed User

• Aug 7, 2021

• #6

Erel said:

Tips:
1. Prefer lists of arrays.
2. Prefer For Each over For i:

B4X:

For Each btn As B4XView In MyButtons
...
Next

Click to expand...

Why For Each is preferable way vs For i ?

 

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Erel

B4X founder

Staff member

Licensed User

Longtime User

• Aug 8, 2021

• #7

It is preferable when you don't need the index.
1. It is safer as you can't get the first or last index wrong:

B4X:

For i = 1 To Arr.Length 'both of them are wrong here
 Dim btn As B4XView = Arr(btn)
 ...
Next

2. It is shorter and more clear:

B4X:

For Each btn As B4XView In Arr

Next

 

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