Easy practice with java variables
Download as PPTX, PDF0 likes266 views
This document discusses variables in Java programming. It explains that variables act like dishes that hold data of a specified type. An example shows declaring an integer variable x and assigning it the value 10, which is correct, while assigning 10 to the variable x would be wrong. It then provides examples of computing areas of shapes like circles and squares using variables to hold values and formulas. The key aspects covered are data types, declaring and assigning values to variables, and using variables in calculations and output.
![circle area
public class CircleArea {
public static void main(String[] args) {
// Declare and initialize the variables
double r=10;
final double PI= 3.1415;
// calculate the circle area
double area = PI*r*r;
// display the result
System.out.print("This is the area of circle: "+area +" u263A");
}
}](https://image.slidesharecdn.com/easypracticewithjavavariables-160819063821/85/Easy-practice-with-java-variables-8-320.jpg)
![Practice in the class
Get area of a square
Formula( area = 𝑎2
)
public class Squarearea {
public static void main(String[] args) {
//Declare variables
double a;
double area;
// Assign value
a=3;
// get the square area
area=a*a;
// display the result
System.out.println("The area of Square with length " +a+ " is: "+ area);
}
}](https://image.slidesharecdn.com/easypracticewithjavavariables-160819063821/85/Easy-practice-with-java-variables-9-320.jpg)
![Rectangle area
public class Rectangle {
public static void main(String[] args) {
int l = 20;
int w =10;
int area = l * w;
System.out.println("The area of rectangle is: "+ area);
}
}](https://image.slidesharecdn.com/easypracticewithjavavariables-160819063821/85/Easy-practice-with-java-variables-11-320.jpg)
Easy practice with java variables
- 1. Easy practice with java variables Java programming Nooria Esmaelzade 2016
- 2. Which one keeps the water?? Which one is preferred?? (A) (B) (C) (D) Of course this one!!
- 3. The dish keeps the water or water keeps the dish??? Of course the dish keeps the water
- 4. To keep the data, we need something like a dish in java Variables can help us here They act like the dish We must define the type of every variable/ dish that holds the data
- 5. Analyze it, which one is the water and which one is the dish and which one is the type of the dish?? int x = 10 ; int 10 = x ; So is it right or wrong?? Data type Variable/ dish Data
- 6. Primitive data types integral ()صحیح floating point()اعشاری Boolean Byte short int long 8-bit 16-bit 32-bit 64-bit Float double 32-bit 64-bit True false
- 7. Compute the circle area formula (𝑎𝑟𝑒𝑎 = 𝜋𝑟2) 1- data holders (variables, constant) 2- assign value and calculate the area 3- display the result
- 8. circle area public class CircleArea { public static void main(String[] args) { // Declare and initialize the variables double r=10; final double PI= 3.1415; // calculate the circle area double area = PI*r*r; // display the result System.out.print("This is the area of circle: "+area +" u263A"); } }
- 9. Practice in the class Get area of a square Formula( area = 𝑎2 ) public class Squarearea { public static void main(String[] args) { //Declare variables double a; double area; // Assign value a=3; // get the square area area=a*a; // display the result System.out.println("The area of Square with length " +a+ " is: "+ area); } }
- 10. Assignment Compute the area of Triangle A = hbb 𝟐 Compute the rectangle area A= width* length
- 11. Rectangle area public class Rectangle { public static void main(String[] args) { int l = 20; int w =10; int area = l * w; System.out.println("The area of rectangle is: "+ area); } }