Guess random number - Printable Version

Guess random number - Printable Version

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+--- Forum: PHP (https://sinister.ly/Forum-PHP)
+--- Thread: Guess random number (/Thread-Guess-random-number)

Pages: 1 2

Guess random number - Vi-Sion - 04-02-2017

this is my first try with php i'm having an error i'm not sure why this is happening hope someone might help .

Spoiler:Code:
<?php
session_start();
if($_SESSION["hasStarted"]!=true){
$_SESSION["number"]=rand(0,20);
$_SESSION["hasStarted"]=true;
$_SESSION["tries"]=0;
}
?>
<html>
<head>
</head>
<body>
<form method="post" action="random.php">
<input type="text" name="number"/>
<input type="submit" value="submit"/>
</form>
<?php 
echo $_SESSION["number"];
if($_POST){
	$_SESSION["tries"]++;
if($_POST["number"]==$_SESSION["number"]){
	$_SESSION["hasStarted"]=false;
	echo $_SESSION["tries"];
	
	 ?><script>alert(<?php echo $_SESSION["tries"];?>);</script>

<a href="random.php">PLAY AGAIN</a>

<?php 
$_SESSION["tries"]=0;
}
else{?>
	<script>alert("false");</script>
	<?php echo $_SESSION["number"];
}}?>
</body>
</html>

The error i'm having is : Notice: Undefined index: hasStarted in C:\xampp\htdocs\test\random.php on line 3

RE: Guess random number - Pikami - 04-02-2017

(04-02-2017, 01:27 PM)Vi-Sion Wrote: The error i'm having is : Notice: Undefined index: hasStarted in C:\xampp\htdocs\test\random.php on line 3

Your problem is written in plain english "Undefined index: hasStarted in C:\xampp\htdocs\test\random.php on line 3"
You are trying to access the variable $_SESSION["hasStarted"] but is is not set.
You can check if a variable is set with the method isset()

RE: Guess random number - Vi-Sion - 04-02-2017

well i know but i heard that in php you don't need to assign a value to a variable before using it.

Code:
In PHP the type of the variable does not need to be declared before use it because types are associated with values rather than variables.

this is quoted from w3resource .

RE: Guess random number - Pikami - 04-02-2017

(04-02-2017, 01:47 PM)Vi-Sion Wrote: well i know but i heard that in php you don't need to assign a value to a variable before using it.

Yes you do.

(04-02-2017, 01:47 PM)Vi-Sion Wrote:
Code:
In PHP the type of the variable does not need to be declared before use it because types are associated with values rather than variables.
this is quoted from w3resource .

This quote states that you don't have to declare variables, witch is right.
But you do have to set a value to a variable before using it.

RE: Guess random number - Vi-Sion - 04-02-2017

i also heard it takes a default value if i didn't give it one so if used as a boolean and didn't give it a value it's default value should be false

RE: Guess random number - Pikami - 04-02-2017

(04-02-2017, 01:55 PM)Vi-Sion Wrote: i also heard it takes a default value if i didn't give it one so if used as a boolean and didn't give it a value it's default value should be false

Yes. In php an unset variable will always give you false.
But in your code, you are trying to access a variable index, that will always trow you an error if it is unset.

RE: Guess random number - Vi-Sion - 04-02-2017

Thanks for your help i got it, much appreciated.

RE: Guess random number - Pikami - 04-02-2017

(04-02-2017, 02:12 PM)Vi-Sion Wrote: Thanks for your help i got it, much appreciated.

I am glad I helped Blush

RE: Guess random number - Vi-Sion - 04-02-2017

Here's my final code i'll be glad to get comments if there's anything i should fix in my code.

Spoiler:Code:
<?php
session_start();
if(isset($_SESSION["hasStarted"])==false){
$_SESSION["number"]=rand(0,100);
$_SESSION["hasStarted"]=true;
$_SESSION["tries"]=0;
}
?>
<html>
<head>
</head>
<body>
<div><p>Guess the hidden number between 0 and 100</p>
<form method="post" action="random.php">
<input type="text" name="number"/>
<input type="submit" value="Guess"/>
</form></div>
<?php 
if($_POST){
 $_SESSION["tries"]++;
if($_POST["number"]==$_SESSION["number"]){
 $_SESSION["hasStarted"]=false;
 ?><script>alert("You've guessed the hidden number after "+<?php echo $_SESSION["tries"];?>+" tries");</script>

<div><a href="random.php">PLAY AGAIN</a></div>
<?php unset($_SESSION["hasStarted"])?>

<?php 
$_SESSION["tries"]=0;
}
else{?>
 <script><?php if($_SESSION["number"]<$_POST["number"]){?>alert("Hidden number is smaller");<?php }?></script>
 <script><?php if($_SESSION["number"]>$_POST["number"]){?>alert("Hidden number is bigger");<?php } ?></script>
 <?php }} ?>
</body>
</html>

RE: Guess random number - FutileRmnc - 11-09-2017

I recommended to using Gaussian Distribution , which implemented as random number generator.

https://en.wikipedia.org/wiki/Normal_distribution
http://mathworld.wolfram.com/NormalDistribution.html
https://natedenlinger.com/php-random-number-generator-with-normal-distribution-bell-curve/

I hope that help , comrade.