by Dinesh Thakur

The const qualifier tells the compiler that the variable's value should not be changed once it has been initialized. If we declare a const variable as

 
by Dinesh Thakur

Boolean operators AND, OR, and NOT are used to manipulate logical statements. Boolean operators are the core operators used in digital control systems as well as computer systems. AND and OR are binary operators, while NOT is a unary operator. Let A and B be two logical statements or variables representing logical statements. If a logical statement is true it may be assigned the value 1, and if a logical statement is false it may be assigned the value 0. Table gives details of the three operators AND, OR, and NOT.



 
by Dinesh Thakur

Arithmetic operators may be combined with the assignment operator to obtain composite assignment operators. An arithmetic operator is written first followed by the assignment operator but not vice versa. In all the composite operators there should not be any blank space between the symbols. For instance, in+= if we give space between+ and= (suchas+ =),it may result in an error.

 
by Dinesh Thakur

We have used the assignment operator (=), which is often called equal to in algebra. On the left of this operator we write the name of variable or l-value to which a value is to be assigned, and on right side we write the value to be assigned to it or r-value. The l-value is the memory segment in which the r-value is stored. Let A, B, and ch is the names of three variables declared as given below.



 
by Dinesh Thakur

 

There are five arithmetic operators, +, -, *, I, and %, which respectively represent the processes of addition, subtraction, multiplication, division, and modulus. The modulus operator (%) gives the remainder when one integer is divided by another integer. All of the five operators have been described with examples of codes in Table.

 
by Dinesh Thakur

The sizeof operator is another method to determine the storage requirements of any data type of variable during the execution of a program. For example, we can use the expression.



 
by Dinesh Thakur

All the objects that are stored in a computer are ultimately converted into binary numbers which are sequences of 0s and 1s. Each digit in a binary number is stored on one bit of the computer memory. A bit is defined as the smallest unit of memory in a computer. In fact, computer manipulates a number by manipulating the bits on which the number is stored. In control systems also we often need to use operators to manipulate bits.



 
by Dinesh Thakur

The C language provides three logical operators that can be used to join relational and equality expressions and form complex Boolean expressions, i. e., expressions with operands having true or false values. These operators include logical AND (&&), logical OR (||) and logical NOT (!). They are summarized in Table.

 
by Dinesh Thakur

The C language provides four relational and two equality operators for comparing the values of expressions. The relational operators are less than (<), greater than (>), less than or equal to (<=) and greater than or equal to (>= ). The equality operators are equal to (==) and not equal to ( ! =). These operators are binary infix operators, i. e., they are used in the form a op b, where a and bare operands (constants, variables or expressions) and op is a relational or an equality operator. Table summarizes these operators.

 
by Dinesh Thakur

The conditional expression operator (? :) is the only ternary operator in the C language. The conditional selection operator(? :) is more convenient to use than if-else provided there are only two options to choose from. It takes three operands and is used to evaluate one of the two alternative expressions depending on the outcome of a test expression as shown below.

 
by Dinesh Thakur

Arithmetic operators are used to perform arithmetic operations on arithmetic operands, i. e., operands of integral as well as floating type. Recall that an integral type includes all forms of char and int types, whereas the floating-point types include the float, double and long double types. These operations include addition (+), subtraction (- ), multiplication (*), division (!), modulo arithmetic (%), increment (++), decrement (-- ), unary plus (+) and unary minus (- ). They can be grouped into three categories: unary operators, multiplicative operators and additive operators. The arithmetic operators are summarized in Table.

 
by Dinesh Thakur

The operator precedence and associativity rules specify the order in which operators in an expression are bound to the operands. These rules enable us to interpret the meaning of an expression in an unambiguous manner.

 
by Dinesh Thakur

Operators are used to connect operands, i. e., constants and variables, to form expressions.

 
by Dinesh Thakur

We can systematically test the value of a variable (or an expression) in a continuous range. Consider that we have to print the result and class obtained by a student in a single subject using the rules given below.

 
by Dinesh Thakur

These statements determine and print the larger of the two variables, x and y,. The variables x, y and z are assumed to be of the same type, say int.. Then we compares the value of variable y with that of variable x.

 
by Dinesh Thakur

In this example we will look at the logical comparison operators. They are six types: &, |, ^,!, && And | |.

 
by Dinesh Thakur

The sizeof operator is used to know the size of variables or types. It returns the size of the type or variable in bytes. We must use it to ensure portability. For example, the size of a whole may depend on the system to which it is building. The sizeof is an operator because it is replaced by the size of the type or variable at compile time. It is not a function. The sizeof admits two ways:

 
by Dinesh Thakur

An operator is a symbol which helps the user to command the computer to do a certain mathematical or logical manipulations. Operators are used in C language program to operate on data and variables. C has a rich set of operators which can be classified as



 
by Dinesh Thakur

An operator is a symbol which helps the user to command the computer to do a certain mathematical or logical manipulations. Operators are used in C language program to operate on data and variables. C has a rich set of operators which can be classified as



 
by Dinesh Thakur

When number of operators occurs in an expression the operator which is to be evaluated first is judged by applying priority of operators. The arithmetic operators available in C are

+ used for Addition

-  used for Subtraction

* used for Multiplication

/ used for Division

 
by Dinesh Thakur

The ++ operator is called the increment operator. When the operator is placed before the variable (++var), the variable is incremented by 1 before it is used in the expression. When the operator is placed after the variable (var++), the expression is evaluated, and then the variable is incremented by 1.

 
by Dinesh Thakur

When a division is performed the remainder of the operation is given by modulus operator. The modulus operator is denoted in c by symbol %. Say for instance we have two integer values x and y and then the operation x % y called as x modulus y gives the result as (x- (x / y) * y).  Say if x=18 and y =5 the x % y gives value as (18- (18 / 5) * 5) which gives (18-15) which results in 3 in other words the remainder of the division operation.

 
by Dinesh Thakur

}The operators present in prefix and postfix are

  • prefix increment operator denoted by ++
  • prefix decrement operator denoted by --
  • postfix increment operator
  • postfix decrement operator
 
by Dinesh Thakur

Example: Suppose in byte that has a value 10101101 . We wish to check whether bit number 3 is ON (1) or OFF (0) . Since we want to check the bit number 3, the second operand for AND operation we choose is binary 00001000, which is equal to 8 in decimal.