Steps in learning C language
| Alphabet Digits Special Symbol |
Constants Variables Keywords |
Instructions | Program |
C Character Set
Following are the valid Characters in C:
| Alphabets | A to Z a to z |
| Digits | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 |
| Special symbols | ~’!@#$%^&*()_-+=|\{}[]:;”<>,.?/ |
Constants, Variables, and Keywords
The combination of alphabets, digits, and special symbols forms constants, variables, and keywords.
A constant is an entity that doesn’t change, whereas a variable may change over the execution of a program and a keyword is a word that has a special meaning in the language.
Types of Constants
C constants are of two types:
(a) Primary Constants
(b) Secondary Constants
| C Constants |
| Primary Constants | Secondary Constants |
| Integer Constants, Real Constants, Character Constants | Array, Pointer, Structure, Union, Enum |
Rules for constructing constant
| Constant | Rules |
| Integer Constant | (i) It must have at least one digit. (ii) It can be positive or negative and must not have decimal point. By default, if the sign is not provided, then it is considered positive. (iii) Range lies between -2147483648 to +2147483648.Example: -555, 31051996, +111 |
| Real Constants | (i) It must have at least one digit. (ii) It can be positive or negative and must have decimal point. By default sign is positive, if the sign is not provided, then it is considered positive. (iii) Range lies between -3.4e38 to 3.4e38.Example: +2.2e-3, 4.1e1 |
| Character Constants | (i) It is a single alphabet, digit, or special character enclosed within a single inverted comma. (ii) Only the left inverted comma is valid i.e. ‘M’.Example: ‘S’, ‘a’ |
also see
| C Programming language |
Go Programming language |
| Linked List | Array |
| Stack | Queue |
| Puzzle | Reasoning |
| Aptitude | HTML |
