> ## Content Index
> Fetch the complete content index at: https://developerinsider.co/llms.txt
> Use this file to discover other available public pages before exploring further.

# Variables declaration in C++
- URL: https://developerinsider.co/variables-declaration-in-cpp/
- Published: 2016-06-03T18:22:27.000Z
- Updated: 2018-03-29T17:00:50.000Z
- Author: Anit Kumar
- Tags: Primary, C++

Creating a variable reserves a memory location, or a space in memory for storing values. The compiler requires that you provide a data type for each variable you declare. Here some point to remember -

- C++ offer a rich assortment of built-in as well as user defined data types.
- Integer, a built-in type, represents a whole number value. Define integer using the keyword int.
- C++ requires that you specify the type and the identifier for each variable defined.
- An identifier is a name for a variable,function,class, module, or any other user-defined item. An identifier starts with a letter`(A-Z or a-z)` or an underscore `(_)`, followed by additional letters, underscore, and digits `(0 to 9)`.  
**For example:**  
Define a variable called var that can hold integer values as follows:  
```  
  int var=10;  
```

Now, let's assign a value to the variable and print it.

```
#include<iostream.h>
using namespace std;
int main()
{
    int var=10;
    cout<<var;
    return 0;
}

```

**Output:**

```
10

```

**Note:** The C++ programming language is case-sensitive, so `var`, `Var` and `VAR` are different-different identifiers.

Define all variables with a name and a data type before using them in a program. In cases in which you have multiple variables of the same type, it's possible to define them in one declaration, separation, separating them with commas(`,`).  
**For example:**

```
int a,b;
//define two variables of type int

```

A variable can be assigned a value, and can be used to perform operations.  
**For example:**

```
int a=30;
int b=15;
int sum =a+b;
cout<<sum;
// Now sum equals 45

```