PHP count_chars() Function: Usage and Examples

Counts byte occurrences and can return a frequency map or filtered bytes.

What Is count_chars() in PHP?

Counts byte occurrences and can return a frequency map or filtered bytes.

Its syntax is:

count_chars(string $string, int $mode = 0): array|string

Parameters:

• $string — Accepted as string; required argument.
• $mode — Accepted as int; optional default 0.

Return type: array|string. Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.

Availability: Core PHP.

Example 1: Basic Usage

<?php

print_r(count_chars("banana", 1));

Output:

Array
(
    [97] => 3
    [98] => 1
    [110] => 2
)

Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.

Example 2: A Different Input

<?php

echo count_chars("abca", 3);

Output:

abc

Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.

Practical Example: Applying It in a Program

<?php

$text = "level"; $frequencies = count_chars($text, 1); foreach ($frequencies as $byte => $frequency) { echo chr($byte) . ": " . $frequency . PHP_EOL; }

Output:

e: 2
l: 2
v: 1

Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.

Important Behavior and Edge Cases

• Key behavior: Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.
• Environment: Core PHP.

Comparison With Related Functions

Common Beginner Mistakes

Key Takeaways

• Counts byte occurrences and can return a frequency map or filtered bytes.
• Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.
• Core PHP.

Summary: Counts bytes, not Unicode characters. Modes 0–2 return arrays; modes 3–4 return strings.