When working with PHP, ord can help with a specific task: returns the numeric value of the first byte of a string.
This guide shows what ord does, how to use it in code, and which details you should check before relying on the result.
What Is ord in PHP?
Returns the numeric value of the first byte of a string.
Usage: The following examples show calls with suitable values. Consult the function parameters described in the examples, especially when optional arguments or extensions are involved.
Example 1: Basic Usage
The first example introduces ord with a direct PHP expression.
<?php
echo ord("A");
Observe the value returned or printed by ord and compare it with the input used in this example.
Example 2: A Different Input or Option
This second example demonstrates another input or condition, so you can compare the behavior with the first example.
<?php
echo ord("ABC");
Observe the value returned or printed by ord and compare it with the input used in this example.
Practical Example
Here is a small scenario illustrating how ord can fit into application code. Run the example only in an appropriate development environment if it reads files, changes data, starts processes or connects to a service.
<?php
$firstByte = ord("Hello"); echo sprintf("0x%02X", $firstByte);
Observe the value returned or printed by ord and compare it with the input used in this example.
Important Behavior and Edge Cases
- Core behavior: Returns the numeric value of the first byte of a string.
- Important limitation: ord() returns a byte value, not a Unicode code point; use mb_ord() for Unicode characters.
- Production use: Check return values and handle failures before acting on the result.
Comparison With Related Functions
| Function or Approach | Difference |
|---|---|
ord() | Returns the numeric value of the first byte of a string. |
chr() | Related approach. Its purpose and return value differ; select it when your task matches that operation. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Overlooking a special case of ord(). | ord() returns a byte value, not a Unicode code point; use mb_ord() for Unicode characters. |
Using ord() without checking the outcome. | Handle failures and confirm that the output is suitable for the next step. |
Key Takeaways
- Returns the numeric value of the first byte of a string.
- ord() returns a byte value, not a Unicode code point; use mb_ord() for Unicode characters.
- Test the function with relevant inputs before using it in production.
Use ord when its behavior matches the job you need to complete. For dependable results, consider the input data, returned value and limitations shown above.