The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its exact value is defined as 299792458 metres per second (approximately 300000 km/s, or 186000 mi/s).

There are three main variables: independent variable, dependent variable and controlled variables.

What is the Difference between Constant and Variables? A constant does not change its value over time. A variable, on the other hand, changes its value dependent on the equation. Constants usually represent the known values in an equation, expression or in line of programming.

Keywords are the words and phrases that people type into search engines to find what they’re looking for. For example, if you were looking to buy a new jacket, you might type something like “mens leather jacket” into Google. Even though that phrase consists of more than one word, it’s still a keyword.

Which variables cannot be declared ?

• structure.
• pointer.
• class.

Answer: KEYWORD: The reserved words of python which have a special fixed meaning for the interpreter are called keywords. No keywords can be used as an identifier. VARIABLE: It is like a container that stores values that can be access or change.

A final variable will occupy memory somewhere at runtime. However where that memory is depends on the kind of variable that you declare as final . If the variable is a local variable or a method’s formal argument variable, then the memory cell will be on the stack.

C variable is a named location in a memory where a program can manipulate the data. This location is used to hold the value of the variable. The value of the C variable may get change in the program. C variable might be belonging to any of the data type like int, float, char etc.