![www.SunilOS.com 23 Binary operators class ExampleAssignment { public static void main(String[] args) { int result, val_1, val_2; result = (val_1 = 1) + (val_2 = 2); System.out.println("val_1 = "+val_1); System.out.println("val_2 = "+val_2); System.out.println("result = "+result); } } class ExampleAssignment { public static void main(String[] args) { int result, val_1, val_2; result = (val_1 = 1) + (val_2 = 2); System.out.println("val_1 = "+val_1); System.out.println("val_2 = "+val_2); System.out.println("result = "+result); } } val_1 = 1 val_2 = 2 result = 3 val_1 = 1 val_2 = 2 result = 3](https://image.slidesharecdn.com/variablesnoperatorsv2-151128123150-lva1-app6891/75/JAVA-Variables-and-Operators-23-2048.jpg)
![www.SunilOS.com 30 Binary operators Expressions connected by && and || are evaluated from left to right. class ExampleAndOr { public static void main(String[] args) { int i=0; System.out.println("Test:" + ((2<3) || (0<i++))); System.out.println("I:" + i); } } class ExampleAndOr { public static void main(String[] args) { int i=0; System.out.println("Test:" + ((2<3) || (0<i++))); System.out.println("I:" + i); } } Test:true I:0 Test:true I:0 This never gets evaluated! This never gets evaluated!](https://image.slidesharecdn.com/variablesnoperatorsv2-151128123150-lva1-app6891/75/JAVA-Variables-and-Operators-30-2048.jpg)
![www.SunilOS.com 45 Mixing operators class MixOperator { public static void main(String[] args) { char cv; int iv1 = 64; cv = (char) iv1; System.out.println("cv:" + cv); System.out.println("iv1:" + iv1); } } cv:@ iv1:64](https://image.slidesharecdn.com/variablesnoperatorsv2-151128123150-lva1-app6891/75/JAVA-Variables-and-Operators-45-2048.jpg)
![www.SunilOS.com 46 Mixing operators class MixOperator1 { public static void main(String[] args) { double fv1, fv2; int iv1 = 123; fv1 = iv1/50; fv2 = iv1/50.0; System.out.println("fv1:" + fv1); System.out.println("fv2:" + fv2); } } fv1:2.0 fv2:2.46 fv1:2.0 fv2:2.46](https://image.slidesharecdn.com/variablesnoperatorsv2-151128123150-lva1-app6891/75/JAVA-Variables-and-Operators-46-2048.jpg)
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JAVA Variables and Operators
The document discusses variables and operators in Java. It defines variables as containers that store data like numbers and letters, and notes that data types determine what values can be stored. It then covers various data types including primitive types like int and float, and reference types like Strings and Arrays. The document also discusses operators like arithmetic, logical, and assignment operators. It provides examples of declaring and using variables and operators in Java code.
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Introduction to the presentation content, focusing on variables and operators.
Variables store human data and are defined by data types. Data types include float, int, char, and boolean.
Data types are classified into primitive (e.g., int, float) and reference types (e.g., String, Arrays).
How to declare variables and instantiate primitive data types, with examples of total and newTotal. Declaring and initializing objects, specifically Strings, and copying their references.
Defining identifiers in Java, including rules about naming variables, methods, and classes.
Introduction to operators as computation triggers, including categories like arithmetic and logical.
Explains the precedence of operators in expressions and the evaluation order.
Details on unary operators such as increment and decrement, with examples.
Analyzes binary operators including arithmetic, comparative, and logical operators with examples.
Covers bitwise operators, their functions, and includes examples of left shift and bitwise operations.Explains the ternary operator and how multiple assignments work in Java.
Details on type conversion, including automatic conversion and explicit casting for different data types.
Demonstration of mixing operator types in Java, showcasing implications in resulting values.
How to convert Strings to other data types and vice versa, using parse methods.
End of the presentation with a disclaimer about educational intent and gratitude for image sources.
JAVA Variables and Operators
- 1. www.SunilOS.com 1 Variables &Operators www.sunilos.com www.raystec.com
- 2. Variables Variable storeshuman data like numbers and alphabets. Data type will decide what values will be stored in variables. You can say data type will define the structure of your data. www.SunilOS.com 2
- 3. Variables and DataTypes Decimal values will be stored in float and double data type. Non-decimals values will be stored in int, long, byte, and short data types. Character will be stored in char data type. True/False will be stored in boolean data type. www.SunilOS.com 3
- 4. www.SunilOS.com 4 Data Types Datatypes are divided into two categories. Primitive Data Types o byte, short, int, long, float, double, boolean, char. o It occupies number of bytes as per data type. o It stores values. Reference Data Types o It stores memory address of a value. o It occupies 2 bytes to store a reference (memory address). o Strings, Objects, Arrays are reference data types.
- 5. www.SunilOS.com 5 Primitive DataTypes int long byte short float double 1 2 4 8 4 8 -128, +127 -9.223E18, +9.223E18 -32768, +32767 -2147483648, +2147483647 +3.4 E+38 +1.7 E+308 Type Size Byte Range char 2 0, 65535 boolean 1 true, false 0 0 0 0 0 0 0 false Default
- 6. www.SunilOS.com 6 Declare Variable inttotal; total = 5+6; short srt; srt = 3; char ch; ch =‘A’ ; 4 Bytes Stack Memory1001 total 1001 11 2 Bytes 1011 3 srt 1011 2 Bytes 1010 A ch 1010
- 7. www.SunilOS.com 7 Declare Object int total; total = 5+6; String str; str = “sunRays”; o or str = new String(“sunRays”); 4 Bytes Stack Memory 1001 total 1001 11 2 Bytes 1011 1010 str 1011 14 Bytes 1010 SUNRAYS
- 8. www.SunilOS.com 8 Declare Variable– Primitive Data int total; total = 5+6; int newTotal; newTotal = total ; newTotal = newTotal+3 ; 4 Bytes Stack Memory1001 total 1001 11 4 Bytes 1011 newTotal 1011 1114
- 9. www.SunilOS.com 9 Declare Object- Copy reference String str; str = “sunRays” Or str = new String(“sunRays”) String newStr; newStr = str; Stack Memory 2 Bytes 1011 1010 str 1011 14 Bytes 1010 SUNRAYS 2 Bytes 1110 1010 newStr 1110
- 10. Java Identifier It isa name of: o Variable o Method o Class o Interface o Package Used to identify a variable, method and class in its scope. www.SunilOS.com 10
- 11. www.SunilOS.com 11 Java IdentifierRules Name of an Identifier follows certain rules. Here are key rules: o The first character must be a non-digit character from the Unicode standard String firstName; o Subsequent characters may include digits int total123 ; o Java is case sensitive that means Character Case is significant • int count =0 ; Count = 1 ; are two different variables o Avoid using underscore (_) and $ for the first character. o User-defined identifiers can not duplicate Java keywords.
- 12. www.SunilOS.com 12 What’s anoperator? Operators are tokens that trigger some computation when applied to variables and other objects. It can be categorized into: o Arithmetic o logical o bit-level and o Class access operators.
- 13. www.SunilOS.com 13 Java operators () ++ -- ! ~ instanceof * / % + - << >> >>> < > <= >= == != & ^ | && || ?: = op=
- 14. www.SunilOS.com 14 Operator Precedence inta = 2+ 4 + 8; int a = 2+ 4 * 8; int a = b = c = 5;
- 15. www.SunilOS.com 15 Operator Precedence OperatorsPrecedence postfix expr++ expr-- unary ++expr --expr +expr -expr ~ ! multiplicative * / % additive + - shift << >> >>> relational < > <= >= instanceof equality == != bitwise AND & bitwise exclusive OR ^ bitwise inclusive OR | logical AND && logical OR || conditional ? : assignment = += -= *= /= %= &= ^= |= <<= >>= >>>=
- 16. www.SunilOS.com 16 Precedence Operators havethe precedence. Higher precedence operator will be evaluated before the lower precedence operator. o int data = a * b + c ; since * (multiply) has higher precedence than + (plus) so a & b will be multiplied first then result will be added to c. Expression is equivalent to o int data = (a * b) + c ;
- 17. www.SunilOS.com 17 Unary operators ()() ++++ Groupexpression Unary plus Unary minus----
- 18. www.SunilOS.com 18 Unary operators ~~~~ !!!! ++++++++ -------- Bitwisecomplement Logical negation Pre- or Post-increment Pre- or Post-decrement
- 19. www.SunilOS.com 19 Unary operators i= 0; count = 2 + i++; i = 0; count = 2 + i++; ii countcount 11 22 i = 0; count = 2 + ++i; i = 0; count = 2 + ++i; ii countcount 11 33
- 20. www.SunilOS.com 20 Binary operators yyyy OperandOperand xxxx OperandOperand OperatorOperator
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- 22. www.SunilOS.com 22 Binary operators ==AssignmentAssignment Assignment is an binary operator in Java. The left-hand operand of an assignment must be an LVALUE. An LVALUE is an expression that refers to a region of memory. o Names of variables are LVALUES. o Names of functions and arrays are NOT LVALUES.
- 23. www.SunilOS.com 23 Binary operators classExampleAssignment { public static void main(String[] args) { int result, val_1, val_2; result = (val_1 = 1) + (val_2 = 2); System.out.println("val_1 = "+val_1); System.out.println("val_2 = "+val_2); System.out.println("result = "+result); } } class ExampleAssignment { public static void main(String[] args) { int result, val_1, val_2; result = (val_1 = 1) + (val_2 = 2); System.out.println("val_1 = "+val_1); System.out.println("val_2 = "+val_2); System.out.println("result = "+result); } } val_1 = 1 val_2 = 2 result = 3 val_1 = 1 val_2 = 2 result = 3
- 24. www.SunilOS.com 24 Binary operators Expressionsinvolving only integers are evaluated using integer arithmetic. float result; int i,j; i=25; j=10; result = i/j; float result; int i,j; i=25; j=10; result = i/j; resultresult 2.02.0
- 25. www.SunilOS.com 25 Binary operators Expressionsinvolving only integers are evaluated using integer arithmetic. float result; int i,j; i=25; j=10; result = (float) i/j; float result; int i,j; i=25; j=10; result = (float) i/j; resultresult 2.52.5
- 26. www.SunilOS.com 26 Binary operators +=+= -=-= *=*= /=/= Assignsum Assign difference Assign product Assign quotient Assign remainder%=%=
- 27. www.SunilOS.com 27 Binary operators Compoundoperators provide a convenient shorthand. int i; i = i + 5; i += 5; int i; i = i + 5; i += 5;
- 28. www.SunilOS.com 28 Binary operators << >> <=<= >=>= Lessthan Greater than Less than or equal to Greater than or equal to Equal to Not equal to Relational == == !=!=
- 29. www.SunilOS.com 29 Binary operators &&&& |||| LogicalAND Logical OR Logical Expressions connected by && and || are evaluated from left to right.
- 30. www.SunilOS.com 30 Binary operators Expressionsconnected by && and || are evaluated from left to right. class ExampleAndOr { public static void main(String[] args) { int i=0; System.out.println("Test:" + ((2<3) || (0<i++))); System.out.println("I:" + i); } } class ExampleAndOr { public static void main(String[] args) { int i=0; System.out.println("Test:" + ((2<3) || (0<i++))); System.out.println("I:" + i); } } Test:true I:0 Test:true I:0 This never gets evaluated! This never gets evaluated!
- 31. www.SunilOS.com 31 Bitwise Binaryoperators << >> & ^ Shift left Shift right Bitwise AND Bitwise XOR Bitwise OR unary bitwise complement unsigned right shift | ~ >>> These operators are less commonly used.
- 32. www.SunilOS.com 32 Unary bitwisecomplement 1 1 11 0 101 ~ 1 Byte 0 0 00 1 010 byte a = 10; byte b = ~a;
- 33. www.SunilOS.com 33 Left Shift<< 1 1 01 0 101 << 1 Byte 1 0 10 0 001 byte a = 10; b = a<<2; 1 1
- 34. www.SunilOS.com 34 Right Shift>> 1 1 01 0 101 >> 1 Byte 1 0 10 1 100 byte a = 10; b = a>>2; 1 0
- 35. www.SunilOS.com 35 Unsigned RightShift >>> 1 1 01 0 101 >>> 1 Byte 0 0 11 1 100 byte a = 10; b = a>>>2; 1 0
- 36. www.SunilOS.com 36 And bitwise& 1 1 01 0 101 & 1 Byte 0 0 11 1 100 byte a = 10; b = 20; c = a & b; 0 0 01 0 100
- 37. www.SunilOS.com 37 OR bitwise| 1 1 01 0 101 | 1 Byte 0 0 11 1 100 byte a = 10; b = 20; c = a | b; 1 1 11 1 101
- 38. www.SunilOS.com 38 XOR bitwise^ 1 1 01 0 101 ^ 1 Byte 0 0 11 1 100 byte a = 10; b = 20; c = a ^ b; 1 1 10 1 001
- 39. www.SunilOS.com 39 Ternary operators a?x:ya?x:y “ifa then x, else y” Conditional result = (x<y) ? x : y;result = (x<y) ? x : y;
- 40. www.SunilOS.com 40 Multiple Assignments inta = b = c = 10;
- 41. www.SunilOS.com 41 Exercise What isthe result of int i = 0 ; System.out.println(++i + ++i + ++i + ++i + ++i + ++i); System.out.println(“” + ++i + ++i + ++i + ++i + ++i + ++i);
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- 43. www.SunilOS.com 43 Small toBig data type Will be done automatically. oint i = 5; odouble d = i; oshort s = 10; oint i = s; olong l = i;
- 44. www.SunilOS.com 44 Big toSmall data type When precision or data loss likely to happen then type casting is required. o double d = 5; o int i = (int)d; o short s = (short)i; o int i = 10; o float f = (float)i;
- 45. www.SunilOS.com 45 Mixing operators classMixOperator { public static void main(String[] args) { char cv; int iv1 = 64; cv = (char) iv1; System.out.println("cv:" + cv); System.out.println("iv1:" + iv1); } } cv:@ iv1:64
- 46. www.SunilOS.com 46 Mixing operators classMixOperator1 { public static void main(String[] args) { double fv1, fv2; int iv1 = 123; fv1 = iv1/50; fv2 = iv1/50.0; System.out.println("fv1:" + fv1); System.out.println("fv2:" + fv2); } } fv1:2.0 fv2:2.46 fv1:2.0 fv2:2.46
- 47. www.SunilOS.com 47 String toOther data type String str = “5.5” ; int i = Integer.parseInt(str); double d = Double.parseDouble(str); float f = Float.parseFloat(str); long l = Long.parseLong(str); String bStr = “true”; boolean b = Boolean.parseBoolean(bStr);
- 48. www.SunilOS.com 48 Other datatype to String String str = String.valueOf(5); String str = String.valueOf(5.5); String str = String.valueOf(true); String str = String.valueOf(5L); String str = String.valueOf(5.5D);
- 49. Disclaimer This is aneducational presentation to enhance the skill of computer science students. This presentation is available for free to computer science students. Some internet images from different URLs are used in this presentation to simplify technical examples and correlate examples with the real world. We are grateful to owners of these URLs and pictures. www.SunilOS.com 49
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