3. Operators (1)_bd5723bb3c1515480be8710ec5c9b1b3.pptx

OPERATORS Introduction Operators are the symbols which operates on value or a variable. It tells the compiler to perform certain mathematical or logical manipulations. Can be of following categories: Unary – requires a single operand Binary – requires two operands Tern...

OPERATORS Introduction Operators are the symbols which operates on value or a variable. It tells the compiler to perform certain mathematical or logical manipulations. Can be of following categories: Unary – requires a single operand Binary – requires two operands Ternary – requires three operands Following are the types of operators: Arithmetic Relational Logical Bitwise Assignment Conditional (ternary) Increment/Decrement Special  Types of operators Types of operators Description Arithmetic operators (binary) These are used to perform mathematical calculations like addition, subtraction, multiplication, division and modulus. Assignment operators (binary) These are used to assign the values for the variables in programs. Relational operators (binary) These operators are used to compare the value of two variables. Logical operators (binary) These operators are used to perform logical operations on the given two variables. Bitwise operators (binary) These operators are used to perform bit operations on given two variables. Conditional operators (ternary) Conditional operators return one value if condition is true and returns another value is condition is false. Increment/Decrement These operators are used to either increase or decrease operators (unary) the value of the variable by one. Special operators sizeof( )  Arithmetic Operators Description Example (A is 10, B is 20) Operato r + Adds two operands A + B will give 30 - Subtracts second operand from the A – B will give -10 first * Multiplies both operands A * B will give 200 / Divides numerator by de- B/A will give 2 and A/B will give 0.5(if numerator float) and 0(if int) %General formOperator Modulus is operand1 operator Boperand2 and remainder % A will give 0 and A % B will give 10 of after an integer division Assignment Operators Operator Description Example = Simple assignment operator, Assigns values from right side operands to left C = A + B will assign value of A + B into C side operand += Compound assignment operator, Add and C += A is equivalent to C = C + A assignment operator. It adds right operand to the left operand and assign the result to left operand -= Compound assignment operator, Subtract C -= A is equivalent to C = C - A and assignment operator. It subtract right operand from the left operand and assign the result to left operand, others would be “ *=, /=, %= “ > 2 &= Bitwise and assignment operator, others C &= 2 is same as C = C & 2 would form General be “^=, is|=“ v op= exp where v is a variable and op is a binary arithmetic operator. This statement is equivalent to v = v op(exp) Relational Operators Operator Description Example (A is 10, B is 20) == Checks if the values of two operands are equal or not, A == B will give 0 if yes then condition becomes true. != Checks if the values of two operands are equal or not, A != B will give 1 if values are not equal then condition becomes true. > Checks if the value of left operand is greater than the A > B will give 0 value of right operand, if yes then condition becomes true. < Checks if the value of left operand is less than the A < B will give 1 value of right operand, if yes then condition becomes true. >= Checks if the value of left operand is greater than or A >= B will give 0 equal to the value of right operand, if yes then condition becomes true. 15) will give 1 non-zero, then condition becomes true. (A>10) && (B>15) will give 0 || Called Logical OR Operator. If any of the two (A>10) || (B>15) will give 1 operands is non-zero, then condition becomes true. ! Called Logical NOT Operator. Use to reverses the (A>10) will give 0 logical state of its operand. If a condition is true then !(A>10) will give 1 Logical NOT operator will make false. General form is operand1 logical-operator operand2 takes a value of 1(int) if the relationship is true and 0(int) if relationship is false. expr1 && expr2 has a value 1 if expr1 and expr2 both are nonzero. expr1 || expr2 has a value 1 if expr1 and expr2, any one of them is nonzero. !expr1 has a value 1 if expr1 is zero else 0.  Bitwise Operators Operator Description Example (A is 60, B is 13) & Binary AND Operator copies a bit to the result if it (A & B) = 12 (0000 1100) exists in both operands. | Binary OR Operator copies a bit if it exists in either (A | B) = 61 (0011 1101) operand. ~ Binary NOT Operator is unary and has the effect of (~A) = -61 (1100 0011 in 2’s 'flipping' bits. complement form) ^ Binary XOR Operator copies the bit if it is set in one (A ^ B) = 49 (0011 0001) operand but not both. Binary Right Shift Operator. The left operand’s value A >> 2 will give 15 which is 0000 is moved right by the number of bits specified by the 1111 right operand. Bit Wise Complement Operator 1.For any integer n, the bitwise complement of n will be -(n+1). 2.Bitwise complement of N = ~N (represented in 2’s complement form). 3.2’complement of ~N= -(~(~N)+1) = -(N+1). Increment/Decrement Operators Increment operators are used to increase the value of the variable by one and decrement operators are used to decrease the value of the variable by one in C programs. Syntax: Increment operator: ++var_name; (or) var_name++; Decrement operator: – -var_name; (or) var_name – -; Conditional Operator Aternary operator pair “?:” is available to construct conditional expression of the form Exp1 ? Exp2 : Exp3 where Exp1, Exp2 and Exp3 are expressions. The operator ?: works as follows: Exp1 is evaluated first. If it is nonzero (true), then the expression Exp2 is evaluated and becomes the value of the expression. If Exp1 is false, Exp3 is evaluated and its value becomes the value of the expression. Syntax (Condition? true_value: false_value); E.g. a = 10; b = 15; x = (a > b) ? a : b Special Operators To get the exact size of a type or a variable on a particular platform, you can use the sizeof operator. The expressions sizeof(type) yields the storage size of the object or type in bytes. int a; sizeof(a)  2 bytes (in 32 bit machine) and 4 bytes (in 64 bit machine) float b; sizeof(b)  4 bytes double c; sizeof(c)  8 bytes char d; sizeof(d)  1 byte Precedence and Associativity Precedence and Associativity are two characteristics of operators that determine the evaluation order of subexpressions in absence of brackets. Please check document of precedence and associativity. Some points: All operators with same precedence have same associativity  This is necessary, otherwise there won’t be any way for compiler to decide evaluation order of expressions which have two operators of same precedence and different associativity. For example + and – have same associativity. Associativity is only used when there are two or more operators of same precedence.  PUMASREBLTAC (PRECEDENCE) TAU (RIGHT TO LEFT) Examples 3+4*4>5*(4+3)-1 x=5,y=5,z z=y + x * y-- + ++x; printf(“%d%d%d”,x,y,z); Example a=0, b=1,c=-1 d= --a*(5+b)/2-c++*b; printf(“%d”,d); THANK YOU ANY QUESTIONS???