Hi guys, in this section we will discuss some basic terminology of C programming language. Here we discuss what is "Constant", "Identifier", "Variable" and many more. So let's get started.
Constant:
- Constants is an entity that has values that can not be changed further. These fixed values are also known as Literals.
- Constants can be of any of the basic data types like an integer constant, a floating point constant, a character constant, or a string literal.
- Constants are many types according to data types such as follows:
- Integer Constants: 1,3,7,89,100...etc.
- Real Constants: 2.3,5.8,7.0...etc.
- Character Constants: 'a', 'b', '@'...etc.
- String Constants: "Hello", "Ram", "Sunil", "DoWithMe"...etc.
Identifiers:
- Identifiers are the names given to variables, constants, functions, and user-defined data types. Examples: int length=10;
- Identifiers must be unique in a particular program.
- We can uniquely identify any entity and other variables with the help of identifiers. Examples: int length; float area; etc.
Variables:
- A variable is a container that stores a value in the memory location, which can be used during the time of execution of the program.
- To indicate the storage area, each variable should've given a unique name i.e. called an identifier.
- Examples: int a = 3; (here a is a variable which stores an integer value)
- The value of a variable can be changed, hence the name variable is justified.
- For Example:
- int length = 10;
- int length = 30;
- The first character must be an alphabet or underscore.
- No commas, blank-space allowed.
- No special symbol is allowed.
- Variables names are case sensitive.
- For better readability make meaningful variables names.
- For example:
- int num=10;
- float area=30.2; etc.
Keywords:
- Keywords are pre-defined reserved words used in programming that have special meanings to the compiler.
- About 32 keywords in C language.
- Keywords are basically written in lowercase letters.
- Keywords can't be used as an identifier.
- For example:
- int num = 10; (here int is the keyword and a is a variable)
Delimiters:
- Delimiters are also known as separators or punctuators.
- They are the characters or symbols that we mainly used to separate values.
- For Examples,
- Comma(,)
- Semicolon(;)
- Colon(:)
- Braces ( {},(),[] )
- Quotes("",' ') ...etc.
That's all for this section, you can also watch videos for more information about this concept.
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