Menu
I've defined a new type Tuple as follows:
subset Tuple of Array where { .elems == 2 && .[0] < .[1] };
my Tuple $t = [1, 2];
say $t; # [1 2] So far, so good.
I can't initialize it with shorter or longer array or with [2, 1], as expected. But, I can append to it:
$t.append(3);
say $t; # [1 2 3] Ouch!
How's that possible?
559
Using sizeof() One way to find the length of an array is to divide the size of the array by the size of each element (in bytes).
An ArrayList can only hold object values. You must decide the size of the array when it is constructed. You can't change the size of the array after it's constructed. However, you can change the number of elements in an ArrayList whenever you want.
The length() method returns the number of characters present in the string. 1. The length variable is applicable to an array but not for string objects whereas the length() method is applicable for string objects but not for arrays.
In a word - yes. You must specify the size of an array when you initialize it.
my Tuple $t creates a $t variable such that any (re)assignment or (re)binding to it must (re)pass the Tuple type check.
= [1, 2] assigns a reference to an Array object. The Tuple type check is applied (and passes).
$t.append(3) modifies the contents of the Array object held in $t but does not reassign or rebind $t so there's no type check.
Mutating-method-call syntax -- $t.=append(3) instead of $t.append(3) -- will trigger the type check on $t.
There is specific syntax for a bounds-checked array (my @array[2] etc.) but I'm guessing that's not the point of your question.
69
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
