How to Convert a Boolean Array to a Decimal Number Using bindec()? A Simple Mapping Method

M66 2025-06-23

In PHP, processing boolean arrays and converting them to decimal numbers is a common requirement, especially in data mapping, access control, or binary flag handling. This article will introduce how to use PHP’s built-in function bindec() along with boolean arrays to achieve a simple and efficient conversion from a boolean array to a decimal number.

1. Introduction to bindec()

bindec() is a PHP function used to convert binary strings into decimal numbers. For example:

<?php
echo bindec("1011"); // Outputs 11
?>

It takes a string consisting of '0' and '1' characters and returns the corresponding decimal integer.

2. Conversion Idea for Boolean Arrays

Elements in a boolean array are true or false, which we can treat as binary digits 1 and 0. For example:

$array = [true, false, true]; // Corresponds to binary 101

The steps are:

Map the boolean array to a string of '1' and '0'.
Use bindec() to convert the string into a decimal number.

3. Code Example

Below is a complete code example that shows how to convert a boolean array into a decimal number:

<?php
// Boolean array
$boolArray = [true, false, true, true]; // Corresponds to binary 1011
<p>// Convert boolean values to '1' or '0'<br>
$binaryString = implode('', array_map(function($b) {<br>
return $b ? '1' : '0';<br>
}, $boolArray));</p>
<p>// Use bindec() to convert to a decimal number<br>
$decimalNumber = bindec($binaryString);</p>
<p>echo "The binary string converted from the boolean array is: " . $binaryString . "\n";<br>
echo "The resulting decimal number is: " . $decimalNumber . "\n";<br>
?><br>

Output:

The binary string converted from the boolean array is: 1011
The resulting decimal number is: 11

4. Application Scenarios

Access Control: Use boolean arrays to represent permissions, convert them to decimal permission codes for storage in a database, making them easier to query.
Flag Mapping: Map multiple boolean flags into a single number for easier data compression and transmission.
State Encoding: Binary encoding of device or system states.

5. Notes

The order of boolean values in the array determines the order of the binary digits, with the first element of the array typically corresponding to the highest bit.
If the boolean array is empty, the conversion result is 0.
If the array contains non-boolean types, it is recommended to perform type checking or conversion first.

6. Advanced Extension: Dynamic Length Mapping

You can convert boolean arrays of any length, which is useful for dynamic flag management:

<?php
function boolArrayToDecimal(array $boolArray): int {
    $binaryString = implode('', array_map(fn($b) => $b ? '1' : '0', $boolArray));
    return bindec($binaryString);
}
<p>// Example call<br>
$flags = [false, true, true, false, true]; // Binary 01101<br>
echo boolArrayToDecimal($flags); // Outputs 13<br>
?><br>

Through the example in this article, you have learned how to use PHP’s bindec() function along with boolean arrays to implement a simple mapping conversion. We hope you can apply this technique in your development to improve coding efficiency and maintainability.

bindec