What is the primary purpose of variables in programming?

The primary purpose of variables in programming is to store and manage data that can be used and manipulated throughout a program. Variables provide a way to label and access data, allowing programmers to store information temporarily, perform calculations, and pass data between functions or parts of a program.

Key purposes of variables include:

1. Storing Values: Variables hold data that can change during the execution of a program.
2. Data Manipulation: Variables allow you to perform operations, such as arithmetic or string manipulations, using stored data.
3. Memory Management: By using variables, data is stored in specific memory locations, which can be accessed by the program when needed.
4. Code Readability: Using meaningful variable names makes the code more readable and easier to understand.

Example:

<span class="pln">
age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">25</span><span class="pln">  </span><span class="com"># 'age' is a variable storing the value 25</span><span class="pln">
</span>

In this example, the variable age stores the value 25 and can be used or modified later in the program.

Python (Dynamic Typing):

<span class="pln">
</span><span class="com"># Variable declaration and initialization</span><span class="pln">
age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">25</span><span class="pln">  </span><span class="com"># Integer</span><span class="pln">
name </span><span class="pun">=</span><span class="pln"> </span><span class="str">"Alice"</span><span class="pln">  </span><span class="com"># String</span><span class="pln">
is_active </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">True</span><span class="pln">  </span><span class="com"># Boolean</span><span class="pln">

</span><span class="com"># Changing value of a variable</span><span class="pln">
age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">26</span><span class="pln">

</span><span class="com"># Accessing variable</span><span class="pln">
</span><span class="kwd">print</span><span class="pun">(</span><span class="pln">name</span><span class="pun">)</span><span class="pln">  </span><span class="com"># Output: Alice</span><span class="pln">
</span>

Java (Static Typing):

<span class="pln">
</span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">Main</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">static</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> main</span><span class="pun">(</span><span class="typ">String</span><span class="pun">[]</span><span class="pln"> args</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
        </span><span class="com">// Variable declaration and initialization</span><span class="pln">
        </span><span class="kwd">int</span><span class="pln"> age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">25</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Integer</span><span class="pln">
        </span><span class="typ">String</span><span class="pln"> name </span><span class="pun">=</span><span class="pln"> </span><span class="str">"Alice"</span><span class="pun">;</span><span class="pln">  </span><span class="com">// String</span><span class="pln">
        </span><span class="kwd">boolean</span><span class="pln"> isActive </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">true</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Boolean</span><span class="pln">

        </span><span class="com">// Changing value of a variable</span><span class="pln">
        age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">26</span><span class="pun">;</span><span class="pln">

        </span><span class="com">// Accessing variable</span><span class="pln">
        </span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="pln">name</span><span class="pun">);</span><span class="pln">  </span><span class="com">// Output: Alice</span><span class="pln">
    </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span><span class="pln">
</span>

C++ (Static Typing):

<span class="pln">
</span><span class="com">#include</span><span class="pln"> </span><span class="str">&lt;iostream&gt;</span><span class="pln">
</span><span class="kwd">using</span><span class="pln"> </span><span class="kwd">namespace</span><span class="pln"> std</span><span class="pun">;</span><span class="pln">

</span><span class="kwd">int</span><span class="pln"> main</span><span class="pun">()</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
    </span><span class="com">// Variable declaration and initialization</span><span class="pln">
    </span><span class="kwd">int</span><span class="pln"> age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">25</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Integer</span><span class="pln">
    </span><span class="kwd">string</span><span class="pln"> name </span><span class="pun">=</span><span class="pln"> </span><span class="str">"Alice"</span><span class="pun">;</span><span class="pln">  </span><span class="com">// String</span><span class="pln">
    </span><span class="kwd">bool</span><span class="pln"> isActive </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">true</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Boolean</span><span class="pln">

    </span><span class="com">// Changing value of a variable</span><span class="pln">
    age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">26</span><span class="pun">;</span><span class="pln">

    </span><span class="com">// Accessing variable</span><span class="pln">
    cout </span><span class="pun">&lt;&lt;</span><span class="pln"> name </span><span class="pun">&lt;&lt;</span><span class="pln"> endl</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Output: Alice</span><span class="pln">
</span><span class="pun">}</span><span class="pln">
</span>

JavaScript (Dynamic Typing):

<span class="pln">
</span><span class="com">// Variable declaration and initialization</span><span class="pln">
</span><span class="kwd">let</span><span class="pln"> age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">25</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Integer</span><span class="pln">
</span><span class="kwd">let</span><span class="pln"> name </span><span class="pun">=</span><span class="pln"> </span><span class="str">"Alice"</span><span class="pun">;</span><span class="pln">  </span><span class="com">// String</span><span class="pln">
</span><span class="kwd">let</span><span class="pln"> isActive </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">true</span><span class="pun">;</span><span class="pln">  </span><span class="com">// Boolean</span><span class="pln">

</span><span class="com">// Changing value of a variable</span><span class="pln">
age </span><span class="pun">=</span><span class="pln"> </span><span class="lit">26</span><span class="pun">;</span><span class="pln">

</span><span class="com">// Accessing variable</span><span class="pln">
console</span><span class="pun">.</span><span class="pln">log</span><span class="pun">(</span><span class="pln">name</span><span class="pun">);</span><span class="pln">  </span><span class="com">// Output: Alice</span><span class="pln">
</span>