Input & Selections

[OliverE]

Input & Selection
​

This tutorial will show you how to apply an input in Java in which a user has to enter a value to get a return in the console.

AgeCalculation
This example is a quick calculation that works out how old a person is depending on their age. (It works out the age by the year, so it may be a year out depending on when you were born in the year.)

[java]import java.util.*;
public class AgeCalc
{
public static void main ( String args [ ] )
{
final int currentYear = 2011; // intialise current year
int ageInYears = 0 ; // initialise variable
Scanner sc = new Scanner (System.in); // create new scanner
System.out.println("What year were you born in ?");
int yearOfBirth = sc.nextInt(); // accept keyboard input
ageInYears = currentYear - yearOfBirth ; // calculate year of birth
System.out.println( "If were born in " + yearOfBirth + " . ") ;
System.out.print( "That means you are "+ageInYears) ;
System.out.println( " years old. " ) ;
}
}[/java]

Thats pritty simple and you should beable to make quite alot just from this tutorial.
Try to take what you have learnt in the above code and apply it to the following tasks below.

Tasks
Try and amend the code below so that customers who are 14 or under get a ticket for £3.99 instead of £9.99.
[java]import java.util.*;
public class Selection
{
public static void main ( String args [] )
{
double price = 9.99;
Scanner sc = new Scanner(System.in);
System.out.print("Enter your age : ");
int age = sc.nextInt();
// code to reduce p r i c e f o r c h i l d r e n
System.out.println("Ticket price= £" + price + ".");
}
[/java]
Hint: It goes along the lines of "If age is equal to or less than 14, price equals 3.99."

Let me know how you get on.
Dont forget to PM with any questions you might have.
First person to figure out what to do gets 1000 bytes.

 

[Charles]

[java]
public class Selection
{
public static void main ( String args [] )
{
double price;
Scanner sc = new Scanner(System.in);
System.out.print("Enter your age : ");
int age = sc.nextInt();

if(age <= 14)
{
price = 3.99;
}
else
{
price = 9.99;
}

System.out.println("Ticket price= £" + price + ".");
}
}
[/java]

 

[OliverE]

Thats it, I had an error in my original code that I input accidently during testing.
So ive fixed it in your code too.

But otherwise that looks good.
Obviously your familar with using the curvy brakets with the IFs.
For simple If statements as in this task, you dont need them.
It will work with or without but its good practice to use them

Here have 1k Bytes

 

[Factor8™]

I'm used to PHP, so I'd probably use the braces as well.

 

[Charles]

Thats it, I had an error in my original code that I input accidently during testing.
So ive fixed it in your code too.

But otherwise that looks good.
Obviously your familar with using the curvy brakets with the IFs.
For simple If statements as in this task, you dont need them.
It will work with or without but its good practice to use them

Here have 1k Bytes

I totally forgot about that lol. I just saw it needed an if statement and plopped one in. I guess you get in the habit of adding them regardless of amount of things-the-function-will-do-if-the-arguments-are-true.

 

[OliverE]

Yep, we will be going through Cases next tutorial.
A much better method of mutliple criterias.