skip same dates in foreach loop - php

Question

this is a text file content which will be chatting database
you:2016-05-02 11:41:53 Hi
Muhammad:2016-05-02 11:42:41 Hi
you:2016-05-02 11:43:33 How are you ?
Muhammad:2016-05-02 14:44:56 I'm fine!
this is the code to loop to get content
<?php
$chat = file("members/cdn/1/chats/9188.txt");
foreach($chat as $line){
$name = strchr($line,":",true);
$message = explode(' ', substr(strchr($line,":"),1), 3);
if(some thing){
?>
<div>
<!-- here i want to skip the same dates -->
<?=$message[0];?>
</div>
<?php
}
?>
<div class="container">
<div class="arrow">
<div class="outer"></div>
<div class="inner"></div>
</div>
<div class="message-body">
<p><?=$message[2];?></p>
<p class="message_time"><?=date("g:i a", strtotime($message[1]));?></p>
</div>
</div>
<div class="spacer"></div>
<?php
}
?>
I want the date of the message appear one time above of messages in the same date

Answer 1

Simply remember that date you last used and then compare it to the one in $message[0]
<?php
$lastDate = NULL;
$chat = file("members/cdn/1/chats/9188.txt");
foreach($chat as $line) :
$name = strchr($line,":",true);
$message = explode(' ', substr(strchr($line,":"),1), 3);
if($lastDate != $message[0]) :
$lastDate = $message[0];
?>
<div><?=$message[0];?></div>
<?php
endif;
?>
<div class="container">
<div class="arrow">
<div class="outer"></div>
<div class="inner"></div>
</div>
<div class="message-body">
<p><?=$message[2];?></p>
<p class="message_time"><?=date("g:i a", strtotime($message[1]));?></p>
</div>
</div>
<div class="spacer"></div>
<?php
endforeach;
?>

Answer 2

Try this:
$prevDate[] = array();
foreach($chat as $line){
$name = strchr($line,":",true);
$message = explode(' ', substr(strchr($line,":"),1), 3);
if(some thing){
?>
<div>
<!-- here i want to skip the same dates -->
<?php
if(!in_array($message[0],$prevDate)) { // check if date exist in array - means displayed previously or not
echo $message[0];
$prevDate = $message[0]; // store date in array so that next time you can check whether it has been already displayed or not
}
?>
</div>
<?php
}
?>
<div class="container">
<div class="arrow">
<div class="outer"></div>
<div class="inner"></div>
</div>
<div class="message-body">
<p><?=$message[2];?></p>
<p class="message_time"><?=date("g:i a", strtotime($message[1]));?></p>
</div>
</div>
<div class="spacer"></div>
<?php
}

Answer 3

First, you can use list assignment to get the components split out into separate vars:
list($user,$date,$time,$message) = explode(' ', substr(strchr($line,":"),1), 4);
Then you can use a simple comparison to see if the date is new:
if ($date != $last_date) {
$last_date = $date;
?><div><?=$date?></div><?php
}
You should declare $last_date before the loop, but you can leave its value undefined.