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PHP Fundamentals
Uploaded :
4 months ago
Updated :
4 months ago
beginner
Take The Quiz
The core of PHP logic
You can store values and echo them. Now learn arrays, conditions, loops and functions.
Arrays
<?php
$fruits = ["apple", "pear", "plum"];
$user = ["name" => "Ada", "age" => 30];
echo $fruits[0]; // apple
echo $user["name"]; // AdaConditions
<?php
if ($score >= 50) {
echo "Pass";
} else {
echo "Try again";
}=== vs ==
Use === for strict comparison (value AND type). == does loose comparison and can surprise you (e.g. 0 == "a").
Loops
<?php
foreach ($fruits as $fruit) {
echo $fruit;
}
for ($i = 0; $i < 3; $i++) {
echo $i;
}Functions
<?php
function add(int $a, int $b): int {
return $a + $b;
}
echo add(2, 3); // 5Useful built-in functions
| Function | What it does | Example |
|---|---|---|
count() | Items in an array | count([1,2,3]) → 3 |
strlen() | Length of a string | strlen("hi") → 2 |
in_array() | Is a value present? | in_array(2, [1,2]) |
implode() | Join an array to text | implode(", ", $a) |
Beware loose typing
PHP converts types automatically. Use === and type hints (int $a) to avoid silent bugs.
Frequently asked questions
What is an associative array?
An array with named keys (
"name" => "Ada") instead of numeric indexes.Do I need type hints?
Not required, but they make code safer and clearer. Modern PHP encourages them.
What does return do?
It sends a value back to the caller and ends the function.
