In computer programming, variables are used to store and manipulate data. Variables are essentially named containers that hold a value that can be changed during the program’s execution.
Here are some key points to understand about variables:
- Declaring a variable: To declare a variable in a program, you need to specify the variable’s name and its data type. For example, you might declare a variable named “count” that is an integer.
- Assigning a value to a variable: Once you have declared a variable, you can assign a value to it using the assignment operator (=). For example, you might assign the value 10 to the “count” variable by writing “count = 10”.
- Changing the value of a variable: During the execution of a program, you can change the value of a variable by assigning a new value to it. For example, you might change the value of the “count” variable from 10 to 20 by writing “count = 20”.
- Using variables in expressions: You can use variables in expressions to perform calculations or manipulate data. For example, you might use the “count” variable in an expression like “total = count * price” to calculate the total cost of an order.
- Scope of variables: Variables can have different scopes, which determine where in the program they can be accessed. Local variables are only accessible within the block of code where they are declared, while global variables can be accessed from any part of the program.