Char Data Type

Introduction

The char data type is a simple data type used to represent a single character. Since computers can only understand binary language, characters need to be encoded in binary format. To do this, we use a popular character set called ASCII. ASCII stands for American Standard Code for Information Interchange which is a system that assigns numeric codes to characters. These codes are in binary, decimal, and hexadecimal format.

A character set is a system that maps characters to their binary representations, allowing computers to work with text correctly. ASCII uses a 7-bit encoding scheme, which means it can represent 128 characters. It includes letters (both uppercase and lowercase), digits, punctuation marks, and control characters. Although there are other character sets like Unicode, ISO-8859, UTF-8, and UTF-16, we’ll focus on ASCII for simplicity in our programs.

It’s important to note that the binary codes of characters can vary from computer to computer because different machines may have different underlying character sets.

Operations on Characters

Characters are internally represented using binary codes, but for our understanding, we can convert each binary code into an integer. In a 7-bit encoding scheme, the integers range from 0 to 127. Interestingly, in the ASCII character set, letters are arranged in consecutive order, which means their assigned numbers are in increasing order.

For example, the lowercase letters ‘a’ to ‘z’ have decimal codes from 97 to 122, while the uppercase letters ‘A’ to ‘Z’ have decimal codes from 65 to 90. This means that characters can be treated as integers in C, and we can perform many operations on them just like we do with integers. Some operations that can be performed on characters include:

Assignment Operation

Characters can be assigned to char variables using the assignment operator.
For example:

char myChar;
myChar = ‘A’;

In the above code snippet, a variable named myChar of type char is declared and assigned the character ‘A’.

Characters are not limited to letters only. In the ASCII character set, digits from 0 to 9 are also part of the character set and can be stored as characters. For instance:

char myChar;
myChar = ‘3’;

The ASCII code for the character ‘3’ is 51.

Additionally, characters can be assigned to variables of type int as well. They will be stored as integers based on their ASCII values. For example:

int x;
x = ‘a’;

After executing this code, the variable “x” will hold the value 97, which corresponds to the ASCII code of the character ‘a’.

Comparison Operations

Characters of type char can be compared using relational operators like equals (==), not equals (!=), less than (<), greater than (>), less than or equal to (<=), and greater than or equal to (>=). These operators compare the ASCII values of the characters.

For example, consider the following code snippet where characters ‘A’ and ‘B’ are compared using the less than (<) operator:

char char1 = 'A';
char char2 = 'B';

if (char1 < char2) {
   printf(“char1 is less than char2);
}

In this case, the output of the program will be “char1 is less than char2” because the ASCII code of the letter ‘A’ (which is 65) is less than the ASCII code of the letter ‘B’ (which is 66).

Arithmetic Operations

Although the char data type is mainly used to represent characters, it can also be involved in arithmetic operations. Internally, characters are represented as integers based on their ASCII values. Therefore, you can perform arithmetic operations on variables of type char.

For example, consider the following code snippet where 1 is added to the character ‘A’:

char myChar = 'A';
myChar = myChar + 1;

After executing this code, the variable myChar will eventually hold the character ‘B’. This is because the ASCII code of ‘A’ (which is 65) added to 1 gives 66, which is the ASCII code of ‘B’.

It is important to note that when performing arithmetic operations on char variables, unexpected results may occur if the resulting value is outside the valid range of characters.

Summary

The char data type is used to represent a single character in C. It can be assigned values, compared using relational operators, and involved in arithmetic operations. Understanding the ASCII character set and its encoding scheme is essential for working with characters effectively.