Variable Scoping

Block Visibility

Variables declared before a block (if, while, for, foreach, switch) are visible inside the block. Modifications to those variables inside the block affect the outer scope.

var total = 0
foreach item in Data.items do
    total += item.price    # Modifies the outer 'total'
end
# total reflects the accumulated sum

Loop Variable Scoping

The iteration variable of a for or foreach loop is scoped to the loop body. It does not exist before the loop and is not accessible after it.

for i in 0 to 5 do
    # i is available here
end
# i is NOT available here

foreach item in Data.items do
    # item is available here
end
# item is NOT available here

Shadowing

An inner var declaration can shadow an outer variable of the same name. The inner variable takes precedence within its scope, and the outer variable is restored when the block exits.

var x = 10
if true then
    var x = 20     # Shadows the outer x
    # x is 20 here
end
# x is 10 here - outer variable is unchanged