php - PHP - foreach loop WITH a condition without additional internal IF statement

Question

I understand that pdo/mysqli is the required standard, for the time being I have no choice other than to use msql

Currently I have this setup to loop through results and display them accordingly

foreach($Items as $Item)
{
    if($Item["Col1"] == "valueFoo"){
        echo "<li>display relevant results</li>";                   
    }
}

Is there way I can do this without looping through the whole array if Items and instead combining the foreach loop with a condition. Alternatively filtering the array prior to the foreachloop? What is the most efficient?

Currently I have 60 items and display them in lists like as below

$SQL = "SELECT * FROM tableName WHERE Col1 IS NOT NULL";
$Data = mysql_query($SQL, $db);

$Items = array();
    while ($NewRow = mysql_fetch_assoc($Data)) {
    // Append all rows to an array
    $Items[] = $NewRow;
}

echo "<ul>";
foreach($Items as $Item)
    {
        if($Item["Col1"] == "valueFoo"){
            echo "<li>display relevant results</li>";                   
        }
    } 
echo "</ul>";
echo "<ul>";
foreach($Items as $Item)
    {
        if($Item["Col1"] == "valueDoo"){
            echo "<li>display relevant results</li>";                   
        }
    } 
echo "</ul>";
echo "<ul>";
foreach($Items as $Item)
    {
        if($Item["Col1"] == "valueHoo"){
            echo "<li>display relevant results</li>";                   
        }
    } 
echo "</ul>";

Is there a more efficient way? I'm still a newbie when it comes to php

score 2 · Accepted Answer

What I'd do is combine each check into one foreach, assigning the text to variables until the end, then echoing them as needed. Inside the foreach use a switch statement to avoid the multiple ifs.

foreach($Items as $Item)
    {
      switch($Item["Col1"])
      {
         case 'valuefoo':
         $result_foo="<li>display relevant results</li>";  
         break;
         case 'valuedoo':
         $result_doo="<li>display relevant results</li>";  
         break;
         case 'valuehoo':
         $result_hoo="<li>display relevant results</li>";  
         break;
         default:
         // handle error if there is one
      }                
        }
    } 
echo "<ul>";
echo $result_foo;
echo "</ul>";

echo "<ul>";
echo $result_doo;
echo "</ul>";

echo "<ul>";
echo $result_hoo;
echo "</ul>";

score 0 · Accepted Answer

You can avoid your multiple foreaches by using this :

in_array(array("Col1" => "valueFoo"), $Items);
// ...
in_array(array("Col1" => "valueDoo"), $Items);
// ...
in_array(array("Col1" => "valueHoo"), $Items);

edit

If you want a better way, replace your whole code by this (see @Maximus2012 comment) :

while ($NewRow = mysql_fetch_assoc($Data)) {
    // Append all rows to an array
    if($NewRow["Col1"] == "valueFoo"){
        $foo = true;                 
    } else if($NewRow["Col1"] == "valueDoo"){
        $doo = true;
    } else if($NewRow["Col1"] == "valueHoo"){
        $hoo = true;
    }
} 

if($foo) {
    echo "<ul>display relevant results</ul>";
}

if($doo) {
    echo "<ul>display relevant results</ul>";
}

if($hoo) {
    echo "<ul>display relevant results</ul>";
}

score 0 · Accepted Answer

I would change how you've ordered the records fetched from the table. So that they are sequenced by Col1 (first, and then other values second) and then you can check for changes in Col1 to start a new <ul> group.

$SQL = "SELECT * FROM tableName WHERE Col1 IS NOT NULL ORDER BY Col1";

If your values for Col1 are fixed values and can be mapped to functions. You could just dispatch calls to local functions of the same name. Otherwise you'll have to use a switch statement.

// create some functions to render each value type
function valueFoo()
{
    echo "<li>display relevant results</li>";
}

function valueHoo()
{
    echo "<li>display relevant results</li>";
}

function valueDoo()
{
    echo "<li>display relevant results</li>";
}

$last_col = false;
foreach($items as $item)
{
    $foo = $item["Col1"];
    if($last_col != $foo)
    {
        if($last_col !== false) echo "</ul>";
        echo "<ul>";
    }
    $foo();
    $last_col = $foo;
}
if($last_col !== false)
{
    echo "</ul>";
}

score 0 · Accepted Answer

You can use something like this:

$ValuesAll = array();

foreach ($Items as $Item) {
    $ValuesAll[$Item['Col1']][] = '<li>' . $Item['Col2'] . '</li>';
}

foreach ($ValuesAll as $Value) {
    echo '<ul>' . implode('', $Value) . '</ul>';
}

This example will create UL for every unique $Item['Col1']. So, if you have Col1 valueFoo, valueDoo, and valueHoo, you will get 3 lists with Col2s for each of Col1.

php - PHP - foreach loop WITH a condition without additional internal IF statement

4 回答 4

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