Can we declare variable without datatype?

Simply put the rule says: “A variable declared without an explicit type name is assumed to be of type int .” If you compile your first example with strict settings adhering to c99 Standard the compiler will tell you the root cause.

What are the rules of declaring a variable in C?

Rules for defining variables

• A variable can have alphabets, digits, and underscore.
• A variable name can start with the alphabet, and underscore only. It can’t start with a digit.
• No whitespace is allowed within the variable name.
• A variable name must not be any reserved word or keyword, e.g. int, goto , etc.

What are three different ways to declare a variable?

Basically we can declare variables in three different ways by using var, let and const keyword.

How do you declare data type?

int height = 2; int width = height * 2; height = height + 1; int area = height * width; The basic built-in C data types are all numeric: char (one byte), int (four bytes), float and double (floating-point numbers), and varieties such as short (short integer), long (long integer), unsigned short, and so on.

How do you declare and initialize a variable?

When you declare a variable, you should also initialize it. Two types of variable initialization exist: explicit and implicit. Variables are explicitly initialized if they are assigned a value in the declaration statement. Implicit initialization occurs when variables are assigned a value during processing.

Can we declare variables anywhere in C?

Modern C compilers such as gcc and clang support the C99 and C11 standards, which allow you to declare a variable anywhere a statement could go. The variable’s scope starts from the point of the declaration to the end of the block (next closing brace). You can also declare variables inside for loop initializers.

How can we declare variable?

To declare (create) a variable, you will specify the type, leave at least one space, then the name for the variable and end the line with a semicolon ( ; ). Java uses the keyword int for integer, double for a floating point number (a double precision number), and boolean for a Boolean value (true or false).