<p data-start="76" data-end="398"><em data-start="76" data-end="118"><strong data-start="77" data-end="117">Introduction to JavaScript Variables<br data-start="118" data-end="121" /> JavaScript provides different ways to declare variables, including <code data-start="188" data-end="193">var</code>, <code data-start="195" data-end="200">let</code>, and <code data-start="206" data-end="213">const</code>. While <code data-start="221" data-end="226">var</code> was traditionally used, <code data-start="251" data-end="258" data-is-only-node="">const</code> has become the preferred choice for immutable values. Understanding their differences is crucial for writing efficient and bug-free code.

<p data-start="400" data-end="678"><em data-start="76" data-end="118"><strong data-start="77" data-end="117">Scope Differences: Global vs. Block Scope<br data-start="447" data-end="450" /> The <code data-start="454" data-end="459">var</code> keyword has function scope, meaning it is accessible throughout the entire function where it is declared. In contrast, <code data-start="579" data-end="586">const</code> has block scope, meaning it is only accessible within the block <code data-start="651" data-end="655">{}</code> where it is defined.

<p data-start="680" data-end="985"><em data-start="76" data-end="118"><strong data-start="77" data-end="117">Hoisting Behavior in <code data-start="704" data-end="709">var</code> and <code data-start="714" data-end="721">const</code><br data-start="724" data-end="727" /> Variables declared with <code data-start="751" data-end="756">var</code> are hoisted to the top of their scope, allowing them to be accessed before their declaration but returning <code data-start="864" data-end="875">undefined</code>. However, <code data-start="886" data-end="893">const</code> is also hoisted but remains in a temporal dead zone until its declaration is encountered.

<p data-start="987" data-end="1264"><em data-start="76" data-end="118"><strong data-start="77" data-end="117">Reassignment and Mutability<br data-start="1020" data-end="1023" /> One of the major differences between <code data-start="1060" data-end="1065">var</code> and <code data-start="1070" data-end="1077">const</code> is reassignment. A variable declared with <code data-start="1120" data-end="1125">var</code> can be reassigned multiple times, while <code data-start="1166" data-end="1173">const</code> prevents reassignment after initialization, making it ideal for storing constant values var vs const<em data-start="76" data-end="118"><strong data-start="77" data-end="117">.

<p data-start="1266" data-end="1567"><em data-start="76" data-end="118"><strong data-start="77" data-end="117">Best Practices for Choosing Between <code data-start="1305" data-end="1310">var</code> and <code data-start="1315" data-end="1322">const</code><br data-start="1325" data-end="1328" /> Using <code data-start="1334" data-end="1341">const</code> is recommended when the value of a variable should not change throughout the program. If reassignment is necessary, <code data-start="1458" data-end="1463">let</code> is a better choice than <code data-start="1488" data-end="1493">var</code>, as it prevents potential issues caused by hoisting and function scope.

<p data-start="1569" data-end="1915" data-is-last-node="" data-is-only-node=""><em data-start="76" data-end="118"><strong data-start="77" data-end="117">Conclusion: Modern JavaScript Encourages <code data-start="1613" data-end="1620">const</code> Over <code data-start="1626" data-end="1631">var</code><br data-start="1634" data-end="1637" /> With the advancements in JavaScript, <code data-start="1674" data-end="1681">const</code> is preferred for defining variables that do not need to change. The use of <code data-start="1757" data-end="1762">var</code> has decreased due to its function scope limitations and potential hoisting issues. Adopting <code data-start="1855" data-end="1862">const</code> ensures better code maintainability and reliability.