A few questions regarding an Array

[discussnow]

Hey, It's me again (the noob learning php).

 

I've gotten to the point where I use the explode function to generate an array. Now i'm moving on to being able to manipulate an array.

 

Basically I want to make it so I can only post results of certain parts of the array.

 

$result[0]

$result[1]

$result[2]

$result[3]

$result[4]

 

If I wanted to only use every other result, for example. How would I do that?

I know it has something to do with $i and $i++ and $i %2 and such.

 

If $i % 2 {print_r $i}

Else $i++

 

God I know my knowledge of this is horrible but I am trying to learn and the only way I can think of is through practicing/learning how to do things.

[bobbinsbro]

$loopCount = count($result);
for($i = 0; $i < $loopCount; $++){
        if (($i % 2) == 0){
            echo $result[$i];
        } 
}

[discussnow]

$loopCount = count($result);
for($i = 0; $i < $loopCount; $++){
        if (($i % 2) == 0){
            echo $result[$i];
        } 
}

 

Thanks! I don't want to just copy paste and actually comprehend so tell me if i'm right.

 

$loopcount means it loops until "count" is met, in this case "count" is the amount in $result?

 

And then in the for part, it will add +1 as long as $i is less then the $loopcount?

 

And the if $i % 2 == 0, that means if $i can be divided by two, then echo result? thanks!

[bobbinsbro]

whoops... i miss-typed the increment...:

$loopCount = count($result);
for($i = 0; $i < $loopCount; ++$i){
        if (($i % 2) == 0){
            echo $result[$i];
        } 
}

 

count() counts the amount of elements in $result array. so the loop goes through all elements of the array, and stops when it runs out of elements (if we tried to access an element that doesn't exist, we would get and error/warning). the reason the count() is not in the for() declaration is because that's better coding practice. doing this:

for($i = 0; $i < Count($result); ++$i){

calls the count() function each iteration of the loop, which is a waste of resources. also, incrementing ++$i is slightly faster in php than $i++.

 

and you got the bit about $i % 2 == 0 right. if that statement is true, we hit an element in an with an even index, so it only echoes every other element. doing $i % 2 == 1 would do the same thing, only with the odd-indexed elements.

[discussnow]

I really appreciate your help!

Will the echo function automatically display the results? Or will I have to string another variable to "catch" all the results pumped out and then print that variable?

 

 

whoops... i miss-typed the increment...:

$loopCount = count($result);
for($i = 0; $i < $loopCount; ++$i){
        if (($i % 2) == 0){
            echo $result[$i];
        } 
}

 

count() counts the amount of elements in $result array. so the loop goes through all elements of the array, and stops when it runs out of elements (if we tried to access an element that doesn't exist, we would get and error/warning). the reason the count() is not in the for() declaration is because that's better coding practice. doing this:

for($i = 0; $i < Count($result); ++$i){

calls the count() function each iteration of the loop, which is a waste of resources. also, incrementing ++$i is slightly faster in php than $i++.

 

and you got the bit about $i % 2 == 0 right. if that statement is true, we hit an element in an with an even index, so it only echoes every other element. doing $i % 2 == 1 would do the same thing, only with the odd-indexed elements.

[bobbinsbro]

echo can print anything that can be converted to a string. basically, anything that isn't an array or an object. so if $result[$i] won't ever be used to store an array or object, echo will always work properly.

 

note: if you do try to echo an array/object, the word "Array"/"Object" (respectively) is printed to the screen.

[discussnow]

As you know taking something from a text box and running them through this php parse. right now Im putting the text in the box and after clicking submit nothing happens. Do i have to set it to echo below the box somehow?

[bobbinsbro]

1. can you repost your current code please?

2. where would you like the text displayed after submit?

[discussnow]

Below it. If I would like to temporarily store it I would need a mysql database set up correct?

<html>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<title>
Paragraph Scrambler
</title>
<body> 
Paste Paragraph <br>
<textarea name="para" type="text" row="5" col="5"></textarea><br>
<input name="send" type="submit" value="Submit!">
<input type="reset" value="Cancel">
</body>
<?php
if(isset($_POST['para'])){
$para  = $_POST['para'];
$result = split('.|\?',$para);
}
$loopCount = count($result);
for($i = 0; $i < $loopCount; $i++){
        if (($i % 2) == 0){
            echo $result[$i];
        }
}
?>

</html>

[bobbinsbro]

if you want the $result printed immediately after the textarea, just move your php block there:

<html>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<title>
Paragraph Scrambler
</title>
<body> 
Paste Paragraph <br>
<textarea name="para" type="text" row="5" col="5"></textarea><br>

<?php
if(isset($_POST['para'])){
$para  = $_POST['para'];
$result = split('.|\?',$para);
}
$loopCount = count($result);
for($i = 0; $i < $loopCount; $i++){
        if (($i % 2) == 0){
            echo $result[$i];
        }
}
?>

<input name="send" type="submit" value="Submit!">
<input type="reset" value="Cancel">
</body>
</html>

 

if you want to store data you have 2 options:

txt file or database. usually, using a database is preferred, but if you intend to store something very small and very simple temporarily, i would avoid the hassle of setting up a database and use a txt file. could you specify what you want to store?

[discussnow]

It's not displaying at all, though, that is the problem.

 

I would like to temporarily store the arrays.

[bobbinsbro]

if(isset($_POST['para'])){
$para  = $_POST['para'];
$result = split('\.|\?',$para);
$loopCount = count($result);
for($i = 0; $i < $loopCount; $i++){
        if (($i % 2) == 0){
            echo $result[$i];
        }
}
}

 

the problem was $result = split('.|\?',$para); there should be a \ before the . so i changed it into $result = split('\.|\?',$para);

 

also i put the loop inside the if(isset()) because you can't display anything if the user hasn't submitted it yes.

 

what do you plan to do with the stored arrays? please be specific so i can recommend most appropriate storage method.

[discussnow]

I plan on taking the array, storing it, then doing a lot of different explodes/loopcounts on it.

[discussnow]

Well I want to take all the data I get from the echo $result and then eventually implode them together. Do I need to store data to do that?

[bobbinsbro]

err... try using a txt file. if things become difficult/inconvenient move to mysql. but it sounds to me like using a database would be a waste of effort.

 

create txt file and write $para into it:

$fh = fopen('somename.txt', 'w'); //create file named somename.txt in the same folder where your php file is. if the file already exists, this will delete it's contents and use it as an empty file.
fwrite($fh, $para); //write the contents of $para into the new file
fclose($fh); //close the file, because until you do, it sits in memory and uses resources.

 

to read txt file:

$fh = fopen('somename.txt', 'r'); //open the file. if it doesn't exist, $fh will contain FALSE
$contents = fgets($fh);//this reads 1 line of the file into $contents

$contents = array();
while ($contents[] = fgets($fh)){ //this reads all lines in file into separate elements in an array.
       continue;
}

fclose($fh); //same as with fopen()

[bobbinsbro]

Well I want to take all the data I get from the echo $result and then eventually implode them together. Do I need to store data to do that?

 

that depends on when you want to implode and use it. if you want to use the data after the script  finishes running, you have to store it in file/DB. other wise, there is no need.

[discussnow]

If Its all in the same script then do I just need to say implode(!, $results) ?

 

[bobbinsbro]

pretty much. but it would be impload("!", $results);

[sasa]

..., incrementing ++$i is slightly faster in php than $i++.

try

<?php

$t = microtime(1);
for ($i=0;$i<100000;$i++);
echo microtime(1)-$t,"\n";

$t = microtime(1);
$b = count($a);
for ($i=0;$i<100000;++$i);
echo microtime(1)-$t,"\n";
?>

[DarkWater]

Or, you could use:

 

$array = array(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10); //example array
foreach (array_filter(array_keys($array), create_function('$x', 'return !($x & 1);')) as $key) {
    echo $array[$key] . "\n";
}

 

Actually, I probably wouldn't use that unless you know what's going on.  I just wanted to see if it could be done with array_filter.

[bobbinsbro]

..., incrementing ++$i is slightly faster in php than $i++.

try

<?php

$t = microtime(1);
for ($i=0;$i<100000;$i++);
echo microtime(1)-$t,"\n";

$t = microtime(1);
$b = count($a);
for ($i=0;$i<100000;++$i);
echo microtime(1)-$t,"\n";
?>

 

i was right this time!:

0.011046886444092

0.0092380046844482

[discussnow]

 

Warning: implode() [function.implode]: Invalid arguments passed in /home/newsexst/public_html/New3.php on line 23

 

Getting this error when adding echo implode(".",$store)

[bobbinsbro]

it seems you introduced new code. please post it.

[discussnow]

<html>
<form method="post" action="<?php echo $_SERVER['PHP_SELF'];?>">
<title>
Paragraph Scrambler
</title>
<body> 
Paste Paragraph <br>
<textarea name="para" type="text" row="5" col="5"></textarea><br>
<input name="send" type="submit" value="Submit!">
<input type="reset" value="Cancel">
</body>
<?php
if(isset($_POST['para'])){
$para  = $_POST['para'];
$result = split('\.|\?',$para);
$loopCount = count($result);
for($i = 0; $i < $loopCount; $i++){
        if (($i % 2) == 0){
            $store = $result[$i];
        }
}
}
echo implode(".",$store);
?>

</html>

[DarkWater]

Change :

$store = $result[$i];

To:

$store[] = $result[$i];