How to display 3 articles in a block, in a cycle

1. PDO should be used instead of mysql_query.
2. Instead of output on the spot, use a template.

Therefore, we do this:

first get the data you need

 $sql = "SELECT * FROM `news` ORDER BY `id` DESC LIMIT 15"; $last_news = $pdo->query($sql)->fetchAll(); 

then break this array into pieces of three lines

 $out = array_chunk($last_news, 3); 

and finally output in the pattern

 <?php foreach($out as $chunk): ?> <div id="r_block"> <?php foreach($chunk as $row): ?> <div> <a href="<?=$row['url']?>"><?=$row['title']?></a> </div> <?php endforeach ?> </div> <?php endforeach ?> 

The approach described in another answer was used in the last century, when no one knew how to write in PHP. And now, writing this way, mixing work with the database, HTML and calculating on your fingers how many lines to print each time - this once again confirms the reputation of PHP as a wretched language that everyone despises. Don't do that.

In short, you can zaminovatov, for what I publish a refutation of the answer @Mike in support of @ Ipatiev ...

But still I will do it ...

and so consider the array_chunk function

 /* {{{ proto array array_chunk(array input, int size [, bool preserve_keys]) Split array into chunks */ PHP_FUNCTION(array_chunk) { int argc = ZEND_NUM_ARGS(), num_in; zend_long size, current = 0; zend_string *str_key; zend_ulong num_key; zend_bool preserve_keys = 0; zval *input = NULL; zval chunk; zval *entry; if (zend_parse_parameters(argc, "al|b", &input, &size, &preserve_keys) == FAILURE) { return; } /* Do bounds checking for size parameter. */ if (size < 1) { php_error_docref(NULL, E_WARNING, "Size parameter expected to be greater than 0"); return; } num_in = zend_hash_num_elements(Z_ARRVAL_P(input)); if (size > num_in) { size = num_in > 0 ? num_in : 1; } array_init_size(return_value, (uint32_t)(((num_in - 1) / size) + 1)); ZVAL_UNDEF(&chunk); ZEND_HASH_FOREACH_KEY_VAL(Z_ARRVAL_P(input), num_key, str_key, entry) { /* If new chunk, create and initialize it. */ if (Z_TYPE(chunk) == IS_UNDEF) { array_init_size(&chunk, (uint32_t)size); } /* Add entry to the chunk, preserving keys if necessary. */ if (preserve_keys) { if (str_key) { entry = zend_hash_update(Z_ARRVAL(chunk), str_key, entry); } else { entry = zend_hash_index_update(Z_ARRVAL(chunk), num_key, entry); } } else { entry = zend_hash_next_index_insert(Z_ARRVAL(chunk), entry); } zval_add_ref(entry); /* If reached the chunk size, add it to the result array, and reset the * pointer. */ if (!(++current % size)) { add_next_index_zval(return_value, &chunk); ZVAL_UNDEF(&chunk); } } ZEND_HASH_FOREACH_END(); /* Add the final chunk if there is one. */ if (Z_TYPE(chunk) != IS_UNDEF) { add_next_index_zval(return_value, &chunk); } } 

And so pay attention to the line

 /* If reached the chunk size, add it to the result array, and reset the * pointer. */ if (!(++current % size)) { add_next_index_zval(return_value, &chunk); ZVAL_UNDEF(&chunk); } 

What does she tell us? the same is correct as in the answer we calculate the remainder of the division by this same size and add the resulting chunk return_value; note the chunk is the link ie physically, this is one variable. While this code is more optimized as it is:

1. Compiled

2. It is typed (there is no type conversion, etc., etc.)

3. A hash of the size from the most needed length is created without a stock (for older versions of php there may be another implementation)

those. in fact, we see that the answer from the T-shirt is a little less than the full functionality of array_chunk and even in speed and in memory consumption, they will be comparable, in certain relative planes.

ps @Mike so I see no reason to write 'not nice' for the sake of dubious optimization.

source code: https://github.com/php/php-src/blob/bd9858ead26f2b1537ca61f3f5a136f8ec160a27/ext/standard/array.c

pps Well, a little argument for coding stait

simple example

  if($num % 3 == 2) echo '</div>'; $num++; 

no mistakes, all is well.

  if($num % 3 == 2) // echo '</div>'; $num++; 

There are no errors, but the algorithm does not work.

more common example

 // тут сотня строк подобного кода if($b == 2) $a = 2; $a=1; // ну и тут так же 

good example seen in coding style for si writing conditions

 if(2 == $a) {} 

cool yes sealed like this if(2=$a) and you got a mistake. and if we examine how we write

 if($a == 2) {} 

and if if($a=2) sealed, then $a is equal to 2, there is no error, the algorithm is not working.

pps I still think that it is necessary to write beautifully and what would work, while in the community where they help, so that the junior would not ask the Temlid, а где ты вот этот кусочек откапал кода? did а где ты вот этот кусочек откапал кода?

 $i = 1; echo( '<div id="r_block">' ); while ($lnews = mysql_fetch_assoc($last_news)) { //разметка if ( $i == 3 ) { echo( '</div><div id="r_block">' ); $i = 1; } else { $i++; } } echo( '</div>' );