// package com.rit; public class JavaLecture6 { public static void main(String[] args) { // Types of Languages // 1 - Statically-typed Languages (C/C++, Java, Scala, C#, Go, Rust, Dart, TS, Kotlin, ...) // - Type checking at compile time // 2 - Dynamically-typed Languages (PHP, Perl, Lua, R, Ruby, JS, Python, Julia, ...) // - Type checking at runtime // Java Data Types // All Java Data-Types are separated into two groups: // 1 - Primitive types or Value types or Simple types // 2 - References types or Non-Primitive types or Object types or Complex types // 1 - Primitive types (storing simple values) // - Java has 8 primitive data types. They can be divided into 4 groups: // - Integer Numbers: byte, short, int, long // - Floating-Point Numbers: float, double // - Logical Type: boolean // - Characters: char // - The most used primitive types are "int", "long", "double", "boolean", and "char". // 2 - References types (storing complex structure/objects) // - String // - Objects // - Arrays // - Classes // - Interfaces // Sizes and Ranges of Primitive types // boolean: It represents only 1-bit of information, but its size is not something that's precisely defined. true or false // byte: the size is 08-bits (1 byte ), the range is from -128 to 127 // char: the size is 16-bits (2 bytes), the range is from 0 to 65536 (unsigned) // short: the size is 16-bits (2 bytes), the range is from -32768 to 32767 // int: the size is 32-bits (4 bytes), // long: the size is 64-bits (8 bytes), // float: the size is 32-bits (4 bytes), approximately 6-7 significant decimal digits // double: the size is 64-bits (8 bytes), approximately 14-16 significant decimal digits // Default Values of Primitive types // boolean - false // char - \u0000 // byte, short, int, long - 0 // float, double - 0.0 // Primitive types Variables byte age = 26; short s = 5569; int v1 = 712928; long v2 = 32_754_921L; long v3 = 4242L; int decNum = 190; int octNum = 0457; int hexNum = 0xFA; int binNum = 0b1101; int minInt = Integer.MIN_VALUE; int maxInt = Integer.MAX_VALUE; float p1 = 424.42F; double p2 = 3523184.428d; double eps = 5e-3; // 5 * 10^(-3) = 0.0005 // System.out.println(Double.SIZE); // 64-bits double minDbl = Double.MIN_VALUE; double maxDbl = Double.MAX_VALUE; char ch = 'C'; char b = 'a' + 1; // the 'b' character char d = 'b' + 2; // the 'd' character char ch1 = 101; // the 'e' character char ch2 = '\u0040'; // the '@' character boolean r1 = true; boolean r2 = false; boolean r3 = 5 > 2; // References types Variables String msg1 = "Java Programming "; String msg2 = new String("Hi Java String"); String newStr = msg1.concat("for Android"); System.out.println(newStr); // Happy Learning :) } }