Java -lec-3
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This document discusses various Java programming concepts including variables, data types, comments, operators, and logical operators. It defines variables as locations that can store data and lists Java's primitive data types like int, float, boolean. The document describes single-line, multi-line and documentation comments in Java. It also explains different types of operators such as assignment, arithmetic, relational, logical, and ternary operators and provides examples of how they work.
Java -lec-3
- 1. JAVA "WRITE ONCE, RUN ANYWHERE” Lec--3 By: Zubair Khalid
- 2. Java £ What is variable £ Data Types in Java £ Comments in Java £ Operators and their types
- 3. Variable is location/place where we can put/store some data. Data can be of different types. E.g. Strings, Numbers etc. Data Types and Variables Variable:
- 4. Data Types and Variables Data type is the type of data which can be stored in a variable. Data Type:
- 5. There are 2 types of built in data types in java Built in Data Types in Java £ Primitive (Non Object Oriented) £ Non-Primitive (Classes, Arrays, Interface)
- 7. £ These Data Types are elemental or simple data types £ Java has 8 primitive types which are following Primitive Types i. Byte ii. Int iii. Short iv. long v. Float vi. Double vii. Boolean viii. char
- 8. Primitive Types Type Meaning Size in bits(Byte) Range Byte 8 bit integer 8(1) -128 to 127 Short Short integer 16(2) -32,768 to 32,767 Int Integer 32(4) -2,147,483,648 to 2,147,483,647 Long Long integer 64(8) -9,223,372,036,854,775,508 to 9,223,372,036,854,775,508 Float Single precision floating point 32(4) Double Double precision floating point 64(8) Boolean True or False value 1 Char Character 16(2) 'u0000' (or 0)-'uffff' (or 65,535 inclusive)
- 9. Java Comments Comments are ignored by compiler and are used to provide summery of code in plain English or any other language. Java defines three types of comments £ Single-Line Comments (//This is Single-line comments) £ Multi-Line Comments (/*This is Multi-line comments*/) £ Documentation Comments (/**This is documentation comment**/)
- 10. Operators An operator is a symbol, which tells the compiler to perform a specific operation There are following types of operators in java Operator: i. Assignment Operator ii. Arithmetic Operators iii. Relational/Conditional Operators iv. Logical Operators
- 11. Assignment Operator Assignment Operator is used to assign a value to a variable E.g. a=10 , b=false , c=‘X’
- 12. Arithmetic Operators Arithmetic Operators perform mathematical operations on variables. Such as Addition, Subtraction, Multiplication, Division, Remainder, Increment and Decrement
- 13. Arithmetic Operators Operator Meaning + Addition - Subtraction * Multiplication / Division % Modulus ++ Increment -- Decrement
- 14. Relational/Conditional Operators Operator Meaning Example == Equal to a==b != Not Equal to a!=b > Greater than a>b < Less than a<b >= Greater than or equal to a>=b <= Less than or equal to a<=b
- 15. Logical Operators Operator Meaning Example & AND x>1 & y<1 | OR x>1 | y<1 ^ XOR(exclusive OR) x ^ y && Short-circuit AND x>1 && y<1 || Short-circuit OR X>1 || y<1 ! NOT x!=1 & y<1
- 16. AND Logic (&) First Value(A) Second Value(B) Result(C) True True True True False False False True False False False False
- 17. OR Logic (|) First Value(A) Second Value(B) Result(C) True True True True False True False True True False False False
- 18. Short-Circuit AND (&&) First Value(A) Second Value(B) Result(C) True True True True False False False True False False False False Checks the first condition if first condition == False Not check second condition elseif first condition == True Check second condition
- 19. Short-Circuit OR (&&) First Value(A) Second Value(B) Result(C) True True True True False True False True True False False False Checks the first condition if first condition == True Not check second condition elseif first condition == False Check second condition
- 20. Ternary Operator Used to replace if-else statement The general form of ternary ? operator is condition ? exp1 : exp2; If (x>10) y=50; else y=20; Example: x=(x>10) ? y=50 : y=20;In to In computer programming, ?: is a ternary operator that is part of the syntax for basic conditional expressions in several programming languages. It is commonly referred to as the conditional operator, inline if (if), or ternary if. An expression a ? b : c evaluates to b if the value of a is true, and otherwise to c.