Array usort() — PHP Technical Interview Questions & Answers

Array usort()

Array usort()

  • Array usort() is a PHP array helper. You pass an array, you get a new array or a boolean/count. Example: in_array(40, $marks), array_merge($a,$b), count($marks).
  • foreach is still how you loop. Functions don’t replace understanding [ ] vs ['name'=>].
  • Trap: expecting the original array to change when the function returns a copy (array_map).

Technical Interview Tip: Array usort(): one array, one function call, say the result.

Code Examples for Array usort()

Array usort() — working example

<?php
$langs = ["PHP", "JS", "SQL"];
$langs[] = "Python";
foreach ($langs as $i => $lang) {
  echo "$i: $lang\n";
}

Array usort() — pHP arrays are ordered maps. foreach walks key and value.

How to Explain Array usort() to an Interviewer

What is Array usort()?

A PHP array helper Try it on $marks = [72,40]