Check if a string starts with given word in PHP

In PHP, you can check if a string starts with a specific word or substring using various methods. The most common approaches include using substr(), strpos(), or the newer str_starts_with() function (PHP 8+).

Using Custom Function with substr()

Create a function that compares the beginning of a string with the specified substring ?

<?php
function begnWith($str, $begnString) {
    $len = strlen($begnString);
    return (substr($str, 0, $len) === $begnString);
}

if(begnWith("pqrstuvwxyz", "pqr")) {
    echo "True! It begins with 'pqr'!";
} else {
    echo "False! It doesn't begin with 'pqr'!";
}
?>

True! It begins with 'pqr'!

Using strpos()

Check if the substring appears at position 0 ?

<?php
function startsWithStrpos($str, $prefix) {
    return strpos($str, $prefix) === 0;
}

$text = "Hello World";
$prefix = "Hello";

if(startsWithStrpos($text, $prefix)) {
    echo "String starts with '$prefix'";
} else {
    echo "String does not start with '$prefix'";
}
?>

String starts with 'Hello'

Using str_starts_with() (PHP 8+)

The modern approach using PHP's built-in function ?

<?php
$text = "Programming with PHP";
$prefix = "Programming";

if(str_starts_with($text, $prefix)) {
    echo "Text starts with '$prefix'";
} else {
    echo "Text does not start with '$prefix'";
}
?>

Text starts with 'Programming'

Comparison

Conclusion

Use str_starts_with() for PHP 8+ projects as it's purpose-built and optimized. For older PHP versions, strpos() === 0 is the fastest approach for checking string prefixes.