6 Programming Instructions
Input
import java.util.Scanner;
public class SampleClass {
public static void main(String[] args) {
// Set variables
String name, age_str;
int age, weight;
// Create a Scanner input object
Scanner user_input = new Scanner(System.in);
// Get user's name
System.out.print("\nYour name: ");
name = user_input.next();
// Get user's age (using .next())
System.out.print("\nYour age, please: ");
age_str = user_input.next();
// convert age from String to integer
age = Integer.parseInt(age_str);
// Get user's weight using .nextInt()
System.out.print("\nHow much do you weigh? ");
weight = user_input.nextInt();
// Test the output:
System.out.println("\nNice to meet you, " + name + ".");
System.out.println("You are " + age + " years old.");
System.out.println("In 5 years, you will be " + (age + 5) +
" years old.");
}
}
Output
Math
public class SampleClass {
public static void main(String[] args) {
/* The Math class & some of its functions */
System.out.println( "The absolute value of -128 is " + Math.abs(-128));
System.out.println( "Between 27 and 25, " + Math.max(27, 25) +
" is greater.");
System.out.println( "Between 27 and 25, " + Math.min(27, 25) +
" is lesser.");
System.out.println( "\nPi as a double is: " + Math.PI);
System.out.println( "3.5 rounded is : " + Math.round(3.5));
System.out.println( "The square root of 42 is " + Math.sqrt(42));
System.out.println( "The square root of 9 is " + (int) Math.sqrt(9));
}
}
public class SampleClass {
public static void main(String[] args) {
// Random (note the differences in the output):
double rand = Math.random();
System.out.println( "\nMath chose " + rand +
" for it's random number.");
System.out.println( "A random number between 0 and 9 is " + Math.random()*10);
System.out.println( "A random integer between 1 and 10 is " +
(int) (Math.random()*10 + 1)); // Note the parentheses
}
}
