# Question: What Happens When A Variable Is Declared?

## What is the difference between constant and variable?

Variable and constant are two commonly used mathematical concepts.

Simply put, a variable is a value that is changing or that have the ability to change.

A constant is a value which remains unchanged..

## What happens when a variable is declared in C?

Variable definition Declaration tells the compiler about data type and size of the variable. Definition allocates memory for the variable. Variable can be declared many times in a program. It can happen only one time for a variable in a program.

## Which variables Cannot be declared?

Which variables cannot be declared ?structure.pointer.class.

## What are the 3 types of variables?

An experiment usually has three kinds of variables: independent, dependent, and controlled. The independent variable is the one that is changed by the scientist.

## How do you define a variable?

A defining variable is a symbol, such as x, used to describe any number. When a variable is used in an function, we know that it is not just one constant number, but that it can represent many numbers. Variables are instrumental in understanding problems relating to graphing.

## What happen a variable is declared as static?

Static variables When a variable is declared as static, then a single copy of variable is created and shared among all objects at class level. Static variables are, essentially, global variables. All instances of the class share the same static variable.

## Why should a variable not be declared?

A variable declared as static means that its value is shared by all instances of this class. Declaring a variable as final gives a slightly better performance and makes your code better readable. local variables are on the stack and are not static. You can have a static field which may or may not be final.

## What happens when a variable goes out of scope?

When a variable goes out of scope, if the object it referred to didn’t have any other strong reference, then the object will be up for garbage collection, whether or not its cleared to null.

## What is variable explain with example?

In mathematics, a variable is a symbol or letter, such as “x” or “y,” that represents a value. … For example, a variable of the string data type may contain a value of “sample text” while a variable of the integer data type may contain a value of “11”.

## What is variable explain?

A variable is a quantity that may change within the context of a mathematical problem or experiment. Typically, we use a single letter to represent a variable. The letters x, y, and z are common generic symbols used for variables.

## What does it mean for a variable to be in scope?

A scope in any programming is a region of the program where a defined variable can have its existence and beyond that variable it cannot be accessed. There are three places where variables can be declared in C programming language − Inside a function or a block which is called local variables.