According to phpbench:

Is it worth the effort to calculate the length of the loop in advance?

Copy//pre-calculate the size of array
$size = count($x); //or $size = sizeOf($x);

for ($i=0; $i<$size; $i++) {
    //...
}

//don't pre-calculate
for ($i=0; $i<count($x); $i++) { //or $i<sizeOf($x);
    //...
}

A loop with 1000 keys with 1 byte values are given.

(time in µs)

So I personally prefer to use count() instead of sizeof() with pre calc.

As alternative you can use array_map

<?php

$strs = array('abcdefgh', 'defghjklmn', 'ghjefggezgzgezg');
$max = 5;
$strs = array_map(function($val) use ($max) {
    if (strlen($val.'') < $max) return $val.'';
    return substr($val.'', 0,$max-3).'...';
},$strs);

var_dump($strs);

EDIT implicit casts added to cast object to string

PHP doesn't have a concept of arrays. It has ordered maps which it calls arrays. They have no finite size. You can't have a fixed size array unless you use the SplFixedArray class

To create PHP's "array" you can use the following syntax.

$myArray = [];

To add elements you use keys. This will map one value to another.

$myArray['myKey'] = 'My string';

You can also use numerical keys or append a new value to the map.

$myArray[42] = 'My string of 42';
$myArray[] = 'Appended value'; // the key will be generated by PHP and will be the next available numerical value

You can use the count function:

echo count($array[3]);

However if the array you want to get the length is not always in this same position you could do something like this:

foreach ($array as $element) {
    if (is_array($element) {
        echo count($element);
    }
}

you can try this:

$a["one"]["two"]["three"]="1";

function count_dimension($Array, $count = 0) {
   if(is_array($Array)) {
      return count_dimension(current($Array), ++$count);
   } else {
      return $count;
   }
}

print count_dimension($a);

You can try the below code. You was adding the below line in the loop that was wrong.

$value = rand(5,10);

Now, This program will return the name that will be equal to the generated random number that is between 5 to 10. Also it will return the message if no name exist according to the random number. For example: 8

<?php
function getName($random_num)
{
    $names = array
    (
        'Juans',
        'Luisss',
        'Pedroaa',
        'testNames1',
        'testNames2',
        'testName3',
        'test', //This should not be return because im only generating a number random of 5-10 and this character has only 4 character length
        'tse', //This should not be return because im only generating a number random of 5-10 and this character has only 3 character length
        // and so on
    );
    $randomString = "";
    for ($i = 0; $i <count($names); $i++)
    {
        $length_string = strlen($names[$i]);
        if ($random_num == $length_string)
        {
            return "name:".$names[$i].$random_num;
        }
    }
}
$random_num = rand(5,10);
$returned_name = getName($random_num);
if ($returned_name == "")
{
    echo "No Name Exist having length: " . $random_num;
}
else
{
    echo $returned_name;
}
?>