Download as PDF, PPTX
![12/1/2020 Vani Kandhasamy,PSG Tech 7
public class Example1 {
public static void main(String[] args) {
int myInt = 9;
double myDouble = myInt; // Automatic casting: int to double
System.out.println(myInt); // Outputs 9
System.out.println(myDouble); // Outputs 9.0
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-7-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 9
class Example2 {
public static void printSquare(int x){
System.out.println("printSquare x = " + x);
x = x * x;
System.out.println("printSquare x = " + x);
}
public static void main(String[] arguments){
int x = 5;
System.out.println("main x = " + x);
printSquare(x);
System.out.println("main x = " + x);
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-9-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 12
class Example3 {
public static void main(String args[]) {
byte b = 42;
char c = 'a';
short s = 1024;
int i = 50000;
float f = 5.67f;
double d = .1234;
double result = (f * b) + (i / c) - (d * s);
System.out.println((f * b) + " + " + (i / c) + " - " + (d * s));
System.out.println("result = " + result);
}
}
Output:
238.14 + 515 - 126.3616
result = 626.7784146484375](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-12-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 16
public class Example5 {
public static void main(String args[]) {
int month = 4; // April
String season;
if(month == 12 || month == 1 || month == 2)
season = "Winter";
else if(month == 3 || month == 4 || month == 5)
season = "Spring";
else if(month == 6 || month == 7 || month == 8)
season = "Summer";
else if(month == 9 || month == 10 || month == 11)
season = "Autumn";
else
season = "Bogus Month";
System.out.println("April is in the " + season + ".");
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-16-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 18
public class Example6 {
public static void main(String args[]) {
String str = "two";
switch(str) {
case "one":
System.out.println("one");
break;
case "two":
System.out.println("two");
break;
case "three":
System.out.println("three");
break;
default:
System.out.println("no match");
break;
}
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-18-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 28
public class Example8 {
public static void main(String args[]) {
int a, b;
for(a=1, b=4; a<b; a++, b--) {
System.out.println("a = " + a);
System.out.println("b = " + b);
}
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-28-2048.jpg)
![Arrays
Syntax: type var_name[ ] = new type [size];
type[ ] var_name;
Example:
double values[ ] = new double [10]
The index starts at zero and ends at length-1
12/1/2020 Vani Kandhasamy,PSG Tech 31](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-31-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 36
public class Example7 {
public static void main(String args[]) {
int nums[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int sum = 0;
for(int x =0; x<nums.length; x++){
System.out.println("Value is: " + x);
sum += nums[x];
}
System.out.println("Summation: " + sum);
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-33-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 37
public class Example7 {
public static void main(String args[]) {
int nums[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
int sum = 0;
// use for-each style for to display and sum the values
for(int x : nums) {
System.out.println("Value is: " + x);
sum += x;
}
System.out.println("Summation: " + sum);
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-34-2048.jpg)
![Multi-
dimensional
Array
12/1/2020 Vani Kandhasamy,PSG Tech 39
int twoD[][] = new int [4][5]
int[][] twoD= new int [4][5]
int []twoD[] = new int [4][5]](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-36-2048.jpg)
![12/1/2020 Vani Kandhasamy,PSG Tech 40
public class Example9 {
public static void main(String args[]) {
int twoD[][]= new int[4][5];
int i, j, k = 0;
for(i=0; i<4; i++)
for(j=0; j<5; j++) {
twoD[i][j] = k;
k++;
}
for(i=0; i<4; i++) {
for(j=0; j<5; j++)
System.out.print(twoD[i][j] + " ");
System.out.println();
}
}
}](https://image.slidesharecdn.com/unit2a-210512071152/75/Java-Basics-Part1-37-2048.jpg)
More Related Content
Similar to Java Basics - Part1
Java Basics - Part1
- 1.
- 2. Overview PART - 1 • Characteristics of Java •Data types, Variables, Operators • Control Statements, Arrays PART - 2 • Classes • Methods, Constructors • Inheritance • Abstract class 12/1/2020 Vani Kandhasamy,PSG Tech 2
- 3. Characteristics of Java Simple Secure Portable Object-oriented Robust Multithreaded Architecture-neutral Interpreted & High performance Distributed Dynamic 12/1/2020 Vani Kandhasamy,PSG Tech 3
- 4.
- 5. Datatypes,Variables, Operators Part 1 –Chapter 3 & 4 12/1/2020 Vani Kandhasamy,PSG Tech 5
- 6. DataTypes Kinds ofvalues that can be stored and manipulated. Java - StronglyTyped Language Automatic Widening casting Boolean: boolean (true or false). Integers: byte, short, int, long (0, 1, -47) Floating point numbers: float, double (3.14, 1.0, -2.1) Characters: char (‘X’, 65) String: String (“hello”, “example”). 12/1/2020 Vani Kandhasamy,PSG Tech 6
- 7. 12/1/2020 Vani Kandhasamy,PSGTech 7 public class Example1 { public static void main(String[] args) { int myInt = 9; double myDouble = myInt; // Automatic casting: int to double System.out.println(myInt); // Outputs 9 System.out.println(myDouble); // Outputs 9.0 } }
- 8. Variables Named locationthat stores a value of one particular type. Syntax: type variable ; (0r) type variable = value; Example: String rollNo; rollNo = “19Z30X”; (or) String rollNo = “19Z30X”; 12/1/2020 Vani Kandhasamy,PSG Tech 8
- 9. 12/1/2020 Vani Kandhasamy,PSGTech 9 class Example2 { public static void printSquare(int x){ System.out.println("printSquare x = " + x); x = x * x; System.out.println("printSquare x = " + x); } public static void main(String[] arguments){ int x = 5; System.out.println("main x = " + x); printSquare(x); System.out.println("main x = " + x); } }
- 10. Practice1 Open repl.it Debug me!!! 12/1/2020Vani Kandhasamy,PSG Tech 10
- 11. Operators Symbols thatperform simple computations Type Promotion Syntax: var = var op expression; (or) var op= expression; Arithmetic operators: (+, -, *, /, …) Assignment operators: (=, +=, -=,…) Relational operators: (==, !=, >, <, …) Logical operators: (&&, ||, !) Bitwise operators: (&, |, ~, …) 12/1/2020 Vani Kandhasamy,PSG Tech 11
- 12. 12/1/2020 Vani Kandhasamy,PSGTech 12 class Example3 { public static void main(String args[]) { byte b = 42; char c = 'a'; short s = 1024; int i = 50000; float f = 5.67f; double d = .1234; double result = (f * b) + (i / c) - (d * s); System.out.println((f * b) + " + " + (i / c) + " - " + (d * s)); System.out.println("result = " + result); } } Output: 238.14 + 515 - 126.3616 result = 626.7784146484375
- 13. Practice2 Open repl.it Compute distancelight travels 12/1/2020 Vani Kandhasamy,PSG Tech 13
- 14. ControlStatements, Arrays Part 1 –Chapter 3 & 5 12/1/2020 Vani Kandhasamy,PSG Tech 14
- 15. 12/1/2020 Vani Kandhasamy,PSGTech 15 Conditional Statements if (CONDITION) { STATEMENTS } if (CONDITION) { STATEMENTS } else { STATEMENTS } if (CONDITION) { STATEMENTS } else if (CONDITION) { STATEMENTS } else { STATEMENTS }
- 16. 12/1/2020 Vani Kandhasamy,PSGTech 16 public class Example5 { public static void main(String args[]) { int month = 4; // April String season; if(month == 12 || month == 1 || month == 2) season = "Winter"; else if(month == 3 || month == 4 || month == 5) season = "Spring"; else if(month == 6 || month == 7 || month == 8) season = "Summer"; else if(month == 9 || month == 10 || month == 11) season = "Autumn"; else season = "Bogus Month"; System.out.println("April is in the " + season + "."); } }
- 17. Selection Statement switch (expression) { casevalue1: // statement sequence break; case value2: // statement sequence break; ... case valueN : // statement sequence break; default: // default statement sequence } 12/1/2020 Vani Kandhasamy,PSG Tech 17
- 18. 12/1/2020 Vani Kandhasamy,PSGTech 18 public class Example6 { public static void main(String args[]) { String str = "two"; switch(str) { case "one": System.out.println("one"); break; case "two": System.out.println("two"); break; case "three": System.out.println("three"); break; default: System.out.println("no match"); break; } } }
- 19.
- 20. Practice3 Open repl.it Identify seasonusing switch 12/1/2020 Vani Kandhasamy,PSG Tech 20
- 21. 2 min 12/1/2020 Vani Kandhasamy,PSGTech 21 Stretch Break
- 22. 12/1/2020 Vani Kandhasamy,PSGTech 22 What if you want to do it for 200 Rules?
- 23. 12/1/2020 Vani Kandhasamy,PSGTech 23 Iterative Statements while (CONDITION) { STATEMENTS } do { STATEMENTS } while (CONDITION); for(initialization;CONDITION;update){ STATEMENTS }
- 24.
- 25.
- 26. 12/1/2020 Vani Kandhasamy,PSGTech 26 S
- 27. 12/1/2020 Vani Kandhasamy,PSGTech 27 r
- 28. 12/1/2020 Vani Kandhasamy,PSGTech 28 public class Example8 { public static void main(String args[]) { int a, b; for(a=1, b=4; a<b; a++, b--) { System.out.println("a = " + a); System.out.println("b = " + b); } } }
- 29. Practice4 Open repl.it Find whethera number is Prime or not 12/1/2020 Vani Kandhasamy,PSG Tech 29
- 30.
- 31. Arrays Syntax: type var_name[] = new type [size]; type[ ] var_name; Example: double values[ ] = new double [10] The index starts at zero and ends at length-1 12/1/2020 Vani Kandhasamy,PSG Tech 31
- 32. 12/1/2020 Vani Kandhasamy,PSGTech 32 Declaration & Instantiation Initialization Declaration, Instantiation & Initialization
- 33. 12/1/2020 Vani Kandhasamy,PSGTech 36 public class Example7 { public static void main(String args[]) { int nums[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int sum = 0; for(int x =0; x<nums.length; x++){ System.out.println("Value is: " + x); sum += nums[x]; } System.out.println("Summation: " + sum); } }
- 34. 12/1/2020 Vani Kandhasamy,PSGTech 37 public class Example7 { public static void main(String args[]) { int nums[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int sum = 0; // use for-each style for to display and sum the values for(int x : nums) { System.out.println("Value is: " + x); sum += x; } System.out.println("Summation: " + sum); } }
- 35. Practice5 Open repl.it Search anarray using for-each style 12/1/2020 Vani Kandhasamy,PSG Tech 38
- 36. Multi- dimensional Array 12/1/2020 Vani Kandhasamy,PSGTech 39 int twoD[][] = new int [4][5] int[][] twoD= new int [4][5] int []twoD[] = new int [4][5]
- 37. 12/1/2020 Vani Kandhasamy,PSGTech 40 public class Example9 { public static void main(String args[]) { int twoD[][]= new int[4][5]; int i, j, k = 0; for(i=0; i<4; i++) for(j=0; j<5; j++) { twoD[i][j] = k; k++; } for(i=0; i<4; i++) { for(j=0; j<5; j++) System.out.print(twoD[i][j] + " "); System.out.println(); } } }
- 38. Practice6 Open repl.it Sum ofprinciple diagonal elements of a matrix 12/1/2020 Vani Kandhasamy,PSG Tech 41
- 39. References "Java:The CompleteReference” by Schildt H - Part 1 - Chapter 3 , 4 & 5 https://www.w3schools.com/java/ 12/1/2020 Vani Kandhasamy,PSG Tech 42