Performance Optimization Techniques

Using const and let provides performance benefits by enabling better JavaScript engine optimizations through block scoping. Unlike var, which is function-scoped and hoisted, const and let are block-scoped, which gives the JavaScript engine more information about how variables are used and when they can be garbage collected. This additional information allows engines to implement more aggressive optimizations, including: 1) Better minification in build tools, 2) More efficient memory management as variables can be garbage collected when they go out of scope at the block level, 3) Easier detection of unused variables, and 4) Prevention of certain types of errors through temporal dead zone checks. Additionally, const provides guarantees about variables not being reassigned, which can enable further compiler optimizations.