[BUG] When i initialize an array with one element it doesn't work

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blink0k

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Posted: 22nd Feb 2016 05:21

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global names as string[0] = [ "cat" ]
global names1 as string[1] = [ "cat", "dog" ]
do  
	print("names[0]="+names[0])
	print("names1[0]="+names1[0]) 
    Sync()
loop

displays';
names[0]=
names1[0]=cat

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CJB

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Posted: 22nd Feb 2016 07:45

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When you define the array, the number in th [] is the number of elements in that array, however when printing the element, the number in the [] is the number of the element to use - starting from 0, and that is key to the problem.

global names as string[0] = [ "cat" ]

means you are creating an array containing zero elements. Change the zero to 1 like this:

global names as string[1] = [ "cat" ]

and then use it like this:

print ( names[0] )

Result =
Cat.

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Scraggle

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Posted: 22nd Feb 2016 08:06

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I don't like that at all!

Although CJB's code does work. The explanation for why it works means that the code should fall over on this line:
global names1 as string[1] = [ "cat", "dog" ]
Because now we are trying to assign the value "dog" to an element of names1 beyond the length of the array.

I believe there is a bug here and the code should work in the way that blink is trying to use it.

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CJB

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Posted: 22nd Feb 2016 08:14 Edited at: 22nd Feb 2016 13:09

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I have to admit, that does look like a bug. At first I thought that by assigning the values of "cat" and "dog" to an array of one string, we were dynamically extending the array, but when trying to add "frog" to the same array, you get an error "Number of default values exceeds array size". So yes, looks like a bug.

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hakimfullmetal

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Posted: 22nd Feb 2016 11:27

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But when I tried to assign "cat" as a string for names[0] manually, the print("names[0]="+names[0]) did shows "cat", instead of an empty string

+ Code Snippet

// Project: Test array 
// Created: 2016-02-22

// set window properties
SetWindowTitle( "Test array" )
SetWindowSize( 1024, 768, 0 )

// set display properties
SetVirtualResolution( 1024, 768 )
SetOrientationAllowed( 1, 1, 1, 1 )


global names as string[0] = [ "cat" ]
names[0] = "cat"
global names1 as string[1] = [ "cat", "dog" ]
do  
    print("names[0]="+names[0])
    print("names1[0]="+names1[0]) 
    Sync()
loop

So this bug only occurs when we tried to assign values to arrays with size of[0], by 'directly' assigning it in this form?
global names as string[0] = [ "cat" ]

But will not occur if we do this?
names[0] = "cat"

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blink0k

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Posted: 22nd Feb 2016 23:04 Edited at: 22nd Feb 2016 23:19

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yes hakimfullmetal. only when initializing a definition.

i think it's an anomaly.
the number in the [] is not in fact the number of elements, it is the index of the last element. ie
array[3] means the array has 4 elements; 0, 1, 2, 3
array[0] means the array has one element 0 but the initialization syntax doesn't seem to work when it's zero
i think the compiler see's zero in the [] and doesn't bother initializing the array
you can also define an empty array like this; array[-1]

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