How to change class of first echo result in PHP? - php

Question

Easy one, but I can't find an answer.
I wanna to list sub-categories to create tabs in code below. This one works fine in my output. But the first tab needs a <li class= "selected" > to show the content on page load .
How to force the first echo result to include a class on <li> element ?
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[ Output ]
Actual: .......... Category 1 | Category 2 | Category 3
Needed: .......... Category 1* | Category 2 | Category 3
*class="selected"
<ul class="cd-tabs-navigation">
<?php
$argumentos = array(
'hide_empty' => 1,
'child_of' => 44,
);
$categories = get_categories($argumentos);
foreach($categories as $category) {
echo '<li><a data-content="' . $category->slug . '" href="#' . $category->slug . '">' . $category->name . '</a></li>';
}
?>
</ul>
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[ EDIT ]
The solution by Lal. Thank you everyone!
foreach($categories as $category) {
if(++$i==1)
echo '<li class="selected"><a class="selected" data-content="' . $category->slug . '" href="#' . $category->slug . '">' . $category->name . '</a></li>';
else
echo '<li><a data-content="' . $category->slug . '" href="#' . $category->slug . '">' . $category->name . '</a></li>';
}

Answer 1

I would suggest you to use a counter.. Not sure if this is the right way to do it..
Change your foreach as follows
$i=0;
foreach($categories as $category) {
if($i==0)
echo '<li class="selected"><a data-content="' . $category->slug . '" href="#' . $category->slug . '">' . $category->name . '</a></li>';
else
echo '<li><a data-content="' . $category->slug . '" href="#' . $category->slug . '">' . $category->name . '</a></li>';
$i++;
}
OR
As suggested in the answer here, you could use array_shift() to process the first item in the array separatley.
That is, do it as below
$first = array_shift($categories);
echo '<li class="selected"><a data-content="' . $first ->slug . '" href="#' . $first ->slug . '">' . $first ->name . '</a></li>';
foreach($categories as $category) {
echo '<li><a data-content="' . $category->slug . '" href="#' . $category->slug . '">' . $category->name . '</a></li>';
}
Read more about array_shift() in the docs

Answer 2

Lal's solution will work fine (as long as you increment $i), but here's a simpler way to do it without an extra variable for the counter :
foreach($categories as $index => $category){
if(!$index) echo "This is the first element";
else echo "This is not the first element";
}
(not sure if this should be an edit or an answer since it's basically the same method but with a slightly simpler synthax, I'll post as an answer for now)

Answer 3

You can use this syntax for foreach. Using this syntax you have in $k the index of the iteration, while in $v the value of the array you're iterating. So if $k == 0 you're in the first iteration.
$a = array("first", "second", "third", "fourth");
foreach ($a as $k=>$v) {
echo $k . "--->" . $v ;
if($k == 0){
echo "First iteration!";
//Do your stuff
}
echo "<br>";
}