In List§

See primary documentation in context for routine sum

sub    sum($list  )
method sum(List:D:)

Returns the sum of all elements in the list or 0 if the list is empty. Throws an exception if an element can not be coerced into Numeric.

say (1, 3, pi).sum;       # OUTPUT: «7.14159265358979␤» 
say (1, "0xff").sum;      # OUTPUT: «256␤» 
say sum(0b1111, 5);       # OUTPUT: «20␤»

If the list includes a Junction, the result will accordingly be a Junction:

say ( 1|2, 3).sum;            # OUTPUT: «any(4, 5)␤» 

When called on native integer arrays, it is also possible to specify a :wrap named parameter. This will add the values as native integers, wrapping around if they exceed the size of a native integer. If you are sure you will not exceed that value, or if you don't mind, using :wrap will make the calculation about 20x as fast.

my int @a = ^1_000_000;
say @a.sum(:wrap);        # OUTPUT: «499999500000␤» 

In Range§

See primary documentation in context for method sum

multi method sum(Range:D:)

Returns the sum of all elements in the Range. Throws X::Str::Numeric if an element can not be coerced into Numeric.

(1..10).sum                                       # 55

In Any§

See primary documentation in context for method sum

method sum() is nodal

If the content is iterable, it returns the sum of the values after pulling them one by one, or 0 if the list is empty.

(3,2,1).sum; # OUTPUT: «6␤» 
say 3.sum;   # OUTPUT: «3␤» 

It will fail if any of the elements cannot be converted to a number.