Introduction to programming with Java - types and variables, conditional statements, loops, arrays

1. Introduction to Java Programming

4. Programming in Java

7. Java API Documentation

8. A Java Program

11. Java Program – Example public class HelloJava { public static void main(String[] args) { System.out.println("Hello, Java!"); } } HelloJava.java javac HelloJava.java java –cp . HelloJava Hello, Java!

14. Structure of Java Programs

19. Programs, Classes, and Packages – Example package jeecourse.example; import java.io.*; public class SomeClass { private static int mValue = 5; public static void printValue() { System.out.println("mValue = " + mValue); } public static void main(String[] args) { System.out.println("Some Class"); printValue(); } }

20. Keywords, Identifiers, Data Types

22. Java Language Keywords abstract continue for new switch assert default goto package synchronized boolean do if private this break double implements protected throw byte else import public throws case enum instanceof return transient catch extends int short try char final interface static void class finally long strictfp volatile const float native super while

30. Ranges of the Integral Primitive Types Type Size Minimum Maximum byte 8 bits -2 7 2 7 – 1 short 16 bits -2 15 2 15 – 1 int 32 bits -2 31 2 31 – 1 long 64 bits -2 63 2 63 – 1

32. Ranges of the Floating-Point Primitive Types Type Size Minimum Maximum float 32 bits +/- 1.40 -45 +/- 3.40 +38 double 64 bits +/- 4.94 -324 +/- 1.79 +308 char 16 bits 0 2 16 - 1

39. Variables, Declarations, Assignments, Operators

41. Variables, Declarations, and Assignments – Examples public class Assignments { public static void main(String args []) { int x, y; // declare int variables float z = 3.414f; // declare and assign float double w = 3.1415; // declare and assign double boolean b = true; // declare and assign boolean char ch; // declare character variable String str; // declare String variable String s = "bye"; // declare and assign String ch = 'A'; // assign a value to char variable str = "Hi out there!"; // assign value to String x = 6; // assign value to int variable y = 1000; // assign values to int variable ... } }

43. Operators Category Operators Unary ++ -- + - ! ~ (type) Arithmetic * / % + - Shift << >> >>> Comparison < <= > >= instanceof == != Bitwise & ^ | Short-circuit && || Conditional ? : Assignment = op=

53. Expressions and Statements

58. If Statement – Example public static void main(String[] args) { int radius = 5; double surface = Math.PI * radius * radius; if (surface > 100) { System.out.println(&quot;The circle is too big!&quot;); } else if (surface > 50) { System.out.println( &quot;The circle has acceptable size!&quot;); } else { System.out.println( &quot;The circle is too small!&quot;); } }

60. The switch Statement – Example int dayOfWeek = 3; switch (dayOfWeek) { case 1: System.out.println(&quot;Monday&quot;); break; case 2: System.out.println(&quot;Tuesday&quot;); break; ... default: System.out.println(&quot;Invalid day!&quot;); break; }

69. Console Input and Output

74. Scanner – Example import java.util.Scanner; public class ScannerDemo { public static void main(String[] args) { Scanner console = new Scanner(System.in); // Get the first input System.out.print(&quot;What is your name? &quot;); String name = console.nextLine(); // Get the second input System.out.print(&quot;How old are you? &quot;); int age = console.nextInt(); // Display output on the console System.out.println(&quot;Hello, &quot; + name + &quot;. &quot; + &quot;Next year, you'll be &quot; + (age + 1)); } }

76. Arrays and Array Manipulation

81. Elements Initialization Element Type Initial Value byte 0 int 0 float 0.0f char ‘ 0000’ object reference null short 0 long 0L double 0.0d boolean false

84. Arrays – Example // Finding the smallest and largest // elements in an array int[] values = {3,2,4,5,6,12,4,5,7}; int min = values[0]; int max = values[0]; for (int i=1; i<values.length; i++) { if (values[i] < min) { min = values[i]; } else if (values[i] > max) { max = values[i]; } } System.out.printf(&quot;MIN=%d&quot;, min); System.out.printf(&quot;MAX=%d&quot;, max);

89. M ulti-dimension al A rrays – Example // Finding the sum of all positive // cells from the matrix int[][] matrix = {{2,4,-3}, {8,-1,6}}; int sum = 0; for (int row=0; row<matrix.length; row++) { for (int col=0; col<matrix[row].length; col++) { if (matrix[row][col] > 0) { sum += matrix[row][col]; } } } System.out.println(&quot;Sum = &quot; + sum);

90. Questions ? Introduction to Java Programming