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C Variables


Variables are containers for storing data values, like numbers and characters.

In C, there are different types of variables (defined with different keywords), for example:

  • int - stores integers (whole numbers), without decimals, such as 123 or -123
  • float - stores floating point numbers, with decimals, such as 19.99 or -19.99
  • char - stores single characters, such as 'a' or 'B'. Characters are surrounded by single quotes

Declaring (Creating) Variables

To create a variable, specify the type and assign it a value:

Syntax

type variableName = value;

Where type is one of C types (such as int), and variableName is the name of the variable (such as x or myName). The equal sign is used to assign a value to the variable.

So, to create a variable that should store a number, look at the following example:

Example

Create a variable called myNum of type int and assign the value 15 to it:

int myNum = 15;

You can also declare a variable without assigning the value, and assign the value later:

Example

// Declare a variable
int myNum;

// Assign a value to the variable
myNum = 15;

Output Variables

You learned from the output chapter that you can output values/print text with the printf() function:

Example

printf("Hello World!");
Try it Yourself »

In many other programming languages (like Python, Java, and C++), you would normally use a print function to display the value of a variable. However, this is not possible in C:

Example

int myNum = 15;
printf(myNum);  // Nothing happens
Try it Yourself »

To output variables in C, you must get familiar with something called "format specifiers", which you will learn about in the next chapter.


C Exercises

Test Yourself With Exercises

Exercise:

Create a variable named myNum and assign the value 50 to it.

  = ;

Start the Exercise



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