The C Constants

In C constants are of two types.
1. Primary constant.
2. Secondary constant.

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Rules for integer constant:

An integer constant must have at least one digit.

It must not have a decimal point.

It can be either positive or negative.

If no sign precedes an integer constant it is assumed to be positive.

No commas or blanks are allowed within an integer constant.

The allowable range for integer constants is -32768 to 32767.

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Must Read

The range vary from compiler to compiler. Here the range is given for 16 bit compiler.

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Rules for real constant:

A real constant must have at least one digit.

It must have a decimal point.

It could be either positive or negative.

Default sign is positive.

No commas or blanks are allowed within a real constant.

The range of real constant is -3.4e38 to 3.4e38. (Where part before e is called mantissa   and part after e is called exponent)

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Rules for character constant:

Character constant is a single alphabet, a single digit or a single special symbol enclosed within single inverted commas. Both the inverted commas should point to the left. For example, ’A’ is a valid character constant whereas ‘A’ is not.

The maximum length of a character constant can be 1 character.

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Must Read

The range vary from compiler to compiler. Here the range is given for 16 bit compiler.

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C Example

#include<stdio.h>

int main() {
	int i=1;
	float a=2.1;
	char c='A';
	printf("%d",i);
	return 0;
}