Master PHP’s ord() Function: Convert Characters to ASCII Values

PHP is a widely used open‑source scripting language for web development. The built‑in function ord() returns the ASCII value of the first character of a given string.

Syntax of ord()

int ord ( string $string )

Parameter description:

string

: The string whose first character’s ASCII value is to be obtained.

Return value:

Returns the ASCII value of the first character of the string.

The ord() function is mainly used to convert a character to its ASCII code. ASCII (American Standard Code for Information Interchange) assigns a unique integer to each character.

Examples of using ord()

Example 1: Get ASCII value of a character

echo ord('A'); // outputs 65
echo ord('B'); // outputs 66
echo ord('a'); // outputs 97
echo ord('b'); // outputs 98

Example 2: Get ASCII value of the first character of a string

echo ord('Hello'); // outputs 72
echo ord('World'); // outputs 87

Example 3: Loop through a string to get ASCII values of each character

$str = 'Hello World';
for ($i = 0; $i < strlen($str); $i++) {
    echo ord($str[$i]) . ' ';
}
// outputs 72 101 108 108 111 32 87 111 114 108 100

The ord() function has limitations with non‑ASCII or multibyte characters; it only handles single‑byte characters and returns the ASCII value of the first byte. For multibyte strings, use mb_ord() instead.

Note that ord() returns 0 for an empty string or when the argument is not a string, so ensure the parameter is a valid string before calling it.

Summary

The ord() function is a built‑in PHP function that retrieves the ASCII value of the first character of a string. It works well for single‑byte characters, but has limitations with multibyte characters; for those, consider using mb_ord().