Thread: Can anyone point me in the right direction with my program?

First of you need ask the user for an input and assign that to a variable.

Now you need loop through the inputted string using the charAt method and check each character within the string to determine if it meets the requirements.

That's a very good little program to get you thinking. There's isn't that many lines of code.

Try the above and code it up, then post what you've got.

We aren't using loops yet. We're using if else statements.

char first = response.charAt(0);
Repeat then for the rest of the requirements.

If(first == 'R')
{
If(nextChar == 'R')
{
}
}

If your not using loops you'll have to use ifs, maybe nested ifs, if your allowed to.

I'm sorry I'm typing on my phone or I'd rattle something better up.

@jeffnine: Please post your code correctly using code or highlight tags which are explained near the top of this link.

import java.util.Scanner;
 
public class Program4 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
 
		String response;
		char R, L;
		boolean Right, Left;
 
		System.out.print("Please enter a lock combination: ");
		response = stdIn.nextLine();
 
		char first = response.charAt(0);
		if (first == 'R')
			Right = true;
		else Right = false;
 
		int second = response.charAt(1);
		if (second == 'd')
			Right = true;
		else Right = false;
 
		int third = response.charAt(2);
		if (third == 'd')
			Right = true;
		else Right = false;
 
		char fourth = response.charAt(3);
		if (fourth == 'L')
			Left = true;
		else Left = false;
 
		int fifth = response.charAt(4);
		if (fifth == 'd')
			Right = true;
		else Right = false;
 
		int sixth = response.charAt(5);
		if (sixth == 'd')
			Right = true;
		else Right = false;
 
		char seventh = response.charAt(6);
		if (seventh == 'R')
			Left = true;
		else Left = false;
 
		int eighth = response.charAt(7);
		if (eighth == 'd')
			Right = true;
		else Right = false;
 
		int ninth = response.charAt(8);
		if (ninth == 'd')
			Right = true;
		else Right = false;
 
 
		if (Right)
			System.out.print( " is a valid lock combination!");
 
		else
			System.out.print( " is not a valid lock combination!");
}}

How do I make it so that the 'd' is a digit between 0-9? Also it's not making the 'R' and the 'L' a unique letter so that only those letters would work in place 0,3,6. Basically anything on the keyboard could be substituted into the 0,3,6 spots and it would work.

Originally Posted by jeffnine

import java.util.Scanner;
 
public class Program4 {
public static void main(String[] args) {
Scanner stdIn = new Scanner(System.in);
 
String response;
char R, L;
boolean Right, Left;
 
System.out.print("Please enter a lock combination: ");
response = stdIn.nextLine();
 
char first = response.charAt(0);
if (first == 'R')
Right = true;
else Right = false;
 
int second = response.charAt(1);
if (second == 'd')
Right = true;
else Right = false;
 
int third = response.charAt(2);
if (third == 'd')
Right = true;
else Right = false;
 
char fourth = response.charAt(3);
if (fourth == 'L')
Left = true;
else Left = false;
 
int fifth = response.charAt(4);
if (fifth == 'd')
Right = true;
else Right = false;
 
int sixth = response.charAt(5);
if (sixth == 'd')
Right = true;
else Right = false;
 
char seventh = response.charAt(6);
if (seventh == 'R')
Left = true;
else Left = false;
 
int eighth = response.charAt(7);
if (eighth == 'd')
Right = true;
else Right = false;
 
int ninth = response.charAt(8);
if (ninth == 'd')
Right = true;
else Right = false;
 
 
if (Right)
System.out.print( " is a valid lock combination!");
 
else
System.out.print( " is not a valid lock combination!");
}}

How do I make it so that the 'd' is a digit between 0-9? Also it's not making the 'R' and the 'L' a unique letter so that only those letters would work in place 0,3,6. Basically anything on the keyboard could be substituted into the 0,3,6 spots and it would work.

I'll take a look at this tomorrow mate post up some additional help when I get In front of PC.

I suggest you fallback and regroup. Follow the requirements for a valid combination given by the assignment and use those requirements one at a time to determine the validity of the user's input.

Also

- in Java variable and method names begin with lowercase letters, and

- comment your code.

import java.util.Scanner;
 
public class Program4 {
	public static void main(String[] args) {
		Scanner stdIn = new Scanner(System.in);
 
		String response; 
		char r, l;
		boolean Right, Left;
 
		System.out.print("Please enter a lock combination: ");
		response = stdIn.nextLine();
 
		new Scanner(System.in);
		char first = response.charAt(0);
		if (first == 'R')
			Right = true;
		else Right = false;
 
		new Scanner(System.in);
		char second = response.charAt(1);
		if (second == 'L')
			Left = true;
		else Left = false;
 
		new Scanner(System.in);
		char third = response.charAt(2);
		if (third == 'R')
			Right = true;
		else Right = false;
 
 
		if (Right)
			System.out.print(first + ("") + second + ("") + third + " is a valid lock combination!");
 
		else
			System.out.print(first + ("") + second + ("") + third + " is not a valid lock combination!");

This code works as expected, just need to get the digits in.

There's a lot of unnecessary code in each of your blocks of code:

new Scanner(System.in);
char first = response.charAt(0);
if (first == 'R')
	Right = true;
else Right = false;

Why the new anonymous Scanner object before each block? The original Scanner object, stdIn, could be reused, but one isn't needed, and the anonymous Scanner object created at the start of each block is completely useless.

What purpose do the variables serve? The code in each block could be reduced to:

// check if first character is an 'R'
if ( response.charAt[0] != 'R' )
{
    validCombo =  false;
}

Again, take each requirement of the assignment at a time:

1. Consists of exactly nine characters.
Write code that checks the length of the input string. Valid if exactly 9 characters.

2. The character at subscripts 0 and 6 must be 'R' - to indicate turning the dial to the right.
Check that the characters at 0 and 6 are 'R' . . .

and so on. Document your code with the requirements, write the code.