Shadowing

When looking at the let variable we've seen that the value can be changed through the use of the mut keyword. We can take this a couple steps further through reassignment and variable shadowing. Note that shadowing applies only to variables. Constants cannot be shadowed.

Reassignment

We can redefine the type and value of a variable by instantiating a new version after the first declaration.

{{#include ../../../code/language/variables/src/lib.sw:reassignment}}

Variable Shadowing

If we do not want to alter the original variable but we'd like to temporarily reuse the variable name then we can use block scope to constrain the variable.

{{#include ../../../code/language/variables/src/lib.sw:shadowing}}

foo is defined inside the curly brackets { } and only exist inside the { .. } scope; therefore, the original foo variable with the value of 5 maintains its value.