Assistance required with basic Rock, Paper, Scissors game - php

Question

I'm new to php and have been struggling to get my rock, paper, scissors game to work! I know what I'm trying to do but just can't get my head aound where I've gone wrong......it works for rock but for paper and scissors I'm getting two outputs!!Please help a novice out...thanks!!
P.S I know there are much slicker ways of doing this!!
<?php
// user enters a value R P or S - NEED TO RETURN A COUPLE OF
TIMES AFTER, not sure why?
echo "What do you select - R for rock, P for paper or S for
scissors?\n";
$input=
$R = stream_get_line(STDIN, 1, "\n");
$P = stream_get_line(STDIN, 1, "\n");
$S = stream_get_line(STDIN, 1, "\n");
//program converts the value into Rock, Paper or Scissors
switch ($input) {
case 'R' :
case 'r':
echo $R = "You selected Rock\n" ;
break;
case 'P' :
case 'p':
echo $P = "You selected Paper\n" ;
break;
case 'S' :
case 's':
echo $S = "You selected Scissors\n" ;
break;
}
//computer generates a random value 0,1,2 & converts to R P or S
echo "\nComputer is now making its selection....\n";
//$options = ('Rock=0, Paper=1, Scissors=2');
$output = (rand(0,2) );
echo $output;
if ($output== 0)
{
echo "\nComputer Selected Rock\n"; //goto Rock;
}
elseif ($output==1)
{
echo "\nComputer Selected Paper\n"; //goto Paper;
}
elseif ($output==2)
{
echo "\nComputer Selected Scissors\n"; //goto Scissors;
}
//compare user and computers choise
Rock:
if ($R && $output===0)//.($P && $output==1),($S && $output==2))
{
echo "\nITS A DRAW";
}
elseif ($R && $output===1)//.($P && $output==2).($S &&
$output==0))
{
echo "\nCOMPUTER WINS";
}
elseif ($R && $output===2)//.($P && $output==0).($S &&
$output==1))
{
echo "\nYOU WIN";
}
Paper:
if ($P && $output===1)
{
echo "\nITS A DRAW";
}
elseif ($P && $output===2)
{
echo "\nCOMPUTER WINS";
}
elseif ($P && $output===0)
{
echo "\nYOU WIN";
}
Scissors:
if ($S && $output===2)
{
echo "\nITS A DRAW";
}
elseif ($S && $output===0)
{
echo "\nCOMPUTER WINS";
}
elseif ($S && $output===1)
{
echo "\nYOU WIN";
}

Answer 1

You should inicialize $R, $P and $S to false first. Then read user input 1x into $input.
The rest of the script seams to be ok.
<?php
$R = $P = $S = false;
$input= stream_get_line(STDIN, 1, "\n");

Answer 2

// user enters a value R P or S - NEED TO RETURN A COUPLE OF TIMES AFTER, not sure why?
because
$input=
$R = stream_get_line(STDIN, 1, "\n");
$P = stream_get_line(STDIN, 1, "\n");
$S = stream_get_line(STDIN, 1, "\n");
You're calling stream_get_line() three times so your script wants three lines of input.
Also, I'm not sure if this was intended, but you're getting your user input seemingly purely by chance as $input = $R = stream_get_line() stores the first user input in $R and $input.
I'd suggest only doing $input = stream_get_line() and nothign else.
Then in your switch/case block you do e.g. echo $R = "..."; and further down you do if ($R && ...).
Evaluating strings as booleans is not recommended.
I would recommend something like
$R = $P = $S = false; // initialize all variables to false
switch ($input)
{
case "R":
$R = true; // set selected variable to true
echo "You have selected Rock\n";
break;
// ...
}
Finally, you seem to be using jump marks to comment your code.
Rock:
if ( ...
While this doesn't cause any problems (yet), it's generally considered bad style to abuse language features for documentation purposes.
These should become comments:
// Rock
if ( ...