Operators and Expressions Operators An operator is symbols

Operators and Expressions

Operators • An operator is symbols that specify operation to be performed may be certain mathematical and logical operation. • Categories of operators are as follows: 1. 2. 3. 4. 5. 6. 7. 8. Arithmetic operators Relational operators Logical operators Assignment operators Increment and decrement operators Conditional operators Bitwise operators Special Operators

Arithmetic operators • Arithmetic operators are used to make mathematical expressions and the working out as same in algebra. • Java provides the fundamental arithmetic operators. • These can operate on built in data type of Java. • Following table shows the details of operators. Operator Importance/ significance + Addition - Subtraction / Division * Multiplication % Modulo division or remainder

Arithmetic operators class Operator. Example{ public static void main(String args[]) { int a=10; int b=5; System. out. println(a+b); 15 System. out. println(a-b); 5 System. out. println(a*b); 50 System. out. println(a/b); 2 System. out. println(a%b); 0 }}

Relational Operators • When evaluation of two numbers is performed depending upon their relation, assured decisions are made. • The value of relational expression is either true or false. • If A=7 and A < 10 is true while 10 < A is false. • Following table shows the details of operators. Operator Importance/ significance > Greater than < Less than != Not equal to >= Greater than or equal to <= Less than or equal to == Is equal to

Relational Operators public class Test { public static void main(String args[]) { int a = 10; int b = 20; System. out. println("a = = b = " + (a = = b) ); System. out. println("a != b = " + (a != b) ); System. out. println("a > b = " + (a > b) ); System. out. println("a < b = " + (a < b) ); System. out. println("b >= a = " + (b >= a) ); System. out. println("b <= a = " + (b <= a) ); }} a == b = false a != b = true a > b = false a < b = true b >= a = true b <= a = false

Logical operators • When we want to form compound conditions by combining two or more relations, then we can use logical operators. Following table shows the details of operators. Operators Importance/ significance || Logical – OR && Logical –AND ! Logical –NOT op 1 && op 2 The logical expression defer a value of true or false

Logical operators public class Test { public static void main(String args[]) { boolean a = true; boolean b = false; System. out. println("a && b = " + (a&&b)); System. out. println("a || b = " + (a||b) ); System. out. println("!(a && b) = " + !(a && b)); } a && b = false } a || b = true !(a && b) = true

Assignment Operator • Assignment Operators is used to assign the value of an expression to a variable and is also called as Shorthand operators. Variable_name binary_operator = expression; • Following table show the use of assignment operators. Simple Assignment Operator Statement with shorthand Operators A=A+1 A=A-1 A=A/(B+1) A=A*(B+1) A=A/C A=A%C A+=1 A-=1 A/=(B+1) A*=(B+1) A/=C A%=C

Assignment Operator class Operator. Example{ public static void main(String[] args){ int a=10; a+=3; 13 System. out. println(a); a-=4; System. out. println(a); 9 a*=2; System. out. println(a); 18 a/=2; System. out. println(a); }} 9

Increment and Decrement Operators • The increment operator ++ adds 1 to a variable. • Usually the variable is an integer type, but it can be a floating point type. Expression A++ ++A A---A Process Add 1 to a variable after use. Add 1 to a variable before use. Subtract 1 from a variable after use. Subtract 1 from a variable before use. Example int A=10, B; B=A++; int A=10, B; B=++A; int A=10, B; B=A--; int A=10, B; B=--A; end result A=11 B=10 A=11 B=11 A=9 B=10 A=9 B=9

Increment and Decrement Operators class Operator. Example{ public static void main(String args[]){ int a=10; int b=10; System. out. println(a++ + ++a); 22 System. out. println(b++ + b++); 21 }}

Increment and Decrement Operators class Operator. Example{ public static void main(String args[]){ int x=10; System. out. println(x++); 10 System. out. println(++x); 12 System. out. println(x--); 12 10 System. out. println(--x); }}

class Increment. Opr { public static void main(String args[]) { int m=10, n=20; m=10 System. out. println(“m=” +m); n=20 System. out. println(“n=” +n); System. out. println(“++m=” + ++m); ++m=11 System. out. println(“n= ” +n++); n++=20 System. out. println(“m=” +m); m=11 System. out. println(“n=” +n); } n=21 }

Conditional Operators • The character pair ? : is a ternary operator of Java, which is used to construct conditional expressions of the following form: Expression 1 ? Expression 2 : Expression 3 • The operator ? : works as follows: • Expression 1 is evaluated if it is true then Expression 2 is evaluated and becomes the value of the conditional expression. • If Expression 1 is false then Expression 3 is evaluated and its value becomes the conditional expression. A=3; B=4; C=(A<B)? A: B; C=(3<4)? 3: 4; Answer C=3

Conditional Operators class Operator. Example{ public static void main(String args[]){ int a=2; int b=5; int min=(a<b)? a: b; System. out. println(min); }} Answer: 2

Bit Wise Operators • These operators are used for testing the bits, or shifting them to right or left. • Following table shows bit wise operator Operator | & &= |= ^ << >> ~ Importance/ significance Bitwise OR Bitwise AND assignment Bitwise OR assignment Bitwise Exclusive OR Left shift Right shift One‘s complement Example: int a= 4; int b = a<<3; Output: b =32

Bit Wise Operators public class Test { public static void main(String args[]) { int a = 60; /* 60 = 0011 1100 */ int b = 13; /* 13 = 0000 1101 */ int c = 0; c = a & b; /* 12 = 0000 1100 */ System. out. println("a & b = " + c ); c = a | b; /* 61 = 0011 1101 */ System. out. println("a | b = " + c ); c = a ^ b; /* 49 = 0011 0001 */ System. out. println("a ^ b = " + c ); c = ~a; /*-61 = 1100 0011 */ System. out. println("~a = " + c ); } } c = a << 2; /* 240 = 1111 0000 */ System. out. println("a << 2 = " + c ); c = a >> 2; /* 15 = 1111 */ System. out. println("a >> 2 = " + c ); c = a >>> 2; /* 15 = 0000 1111 */ System. out. println("a >>> 2 = " + c );

Special Operators • Java supports some special operators of interest such as instanceof operator and member selection operator (. ). • Instanceof Operator : • The instanceof is an object reference operator and returns true if the object on the left hand is an instance of the class given on right-hand side person instanceof student • Dot Operator : • The dot operator (. ) is used to access the instance variable and methods of class object. Person 1. age Person 1. salary()

Operator Precedence in Java: • An arithmetic expression without any parentheses will be calculated from left to right using the rules of precedence of operators. • There are two priority levels of arithmetic operators are as follows: • High priority (* / %) • Low priority (+ -)

Operator [] (). ++ -! ~ (type) * / % + << >> >>> Associativity Left to right Right to left Right to left Left to right Left to right Rank 1 2 3 4 5 < <= > >= Instanceof == != & ^ | && || ? : = Left to right Left to right Left to right Right to left 6 7 8 9 10 11 13 13 14

Mathematical Functions • Mathematical Functions such as cos, sqrt, log, etc. are frequently used. • Java supports these functions through Math class defined in java. lang package. • These functions should be used as following : Math. function_name(); Example : double y= Math. sqrt(x); Function sqrt() sin() ceil() cos() floor() tan() round() pow(x, y) abs(a) exp(x) max(a, b) log(x) min(a, b)