When working with PHP, you may need to replace named placeholders in an ICU message pattern. This guide explains the operation, shows what its arguments mean, and uses three separate examples to make the result easier to understand.
MessageFormatter::format: Placeholders can be named and can apply number or plural formatting rules.
What Is MessageFormatter::format in PHP?
Replace named placeholders in an ICU message pattern. Placeholders can be named and can apply number or plural formatting rules.
Syntax:
$formatter->format(array $values): string|false
Parameters and return value: The signature above identifies the arguments and return type where the API has a single call. For topic guides, follow the sequence of calls in the examples. Always distinguish a returned value from an object or variable modified by reference.
Important: Missing arguments or invalid ICU patterns may produce false; do not concatenate false as a successful message.
Example 1: Basic Usage
This example introduces the operation with a short and predictable input.
<?php
$formatter = new MessageFormatter("en_US", "Hello, {name}!");
echo $formatter->format(["name" => "Alex"]);
The code focuses on the main operation. Placeholders can be named and can apply number or plural formatting rules.
Example 2: Another Case
Now compare a different input, locale, date, or option to see another part of the behavior.
<?php
$formatter = new MessageFormatter("en_US", "Total: {amount, number}");
echo $formatter->format(["amount" => 1234.5]);
What changes? Missing arguments or invalid ICU patterns may produce false; do not concatenate false as a successful message.
Practical Example: Applying It in an Application
Use the following separate example as a starting point for a small application task. Check any extension or environment requirements below before running it.
<?php
$formatter = new MessageFormatter("en_US", "{count, plural, one{# result} other{# results}}");
foreach ([1, 4] as $count) {
echo $formatter->format(["count" => $count]) . PHP_EOL;
}
The practical example demonstrates how to apply this operation to multiple values, a reusable task, or a validated input. Placeholders can be named and can apply number or plural formatting rules.
Important Behavior and Edge Cases
- Core behavior: Placeholders can be named and can apply number or plural formatting rules.
- Inputs and results: Missing arguments or invalid ICU patterns may produce false; do not concatenate false as a successful message.
- Alternatives: MessageFormatter::formatMessage() is convenient for one-off formatting.
- Compatibility: The intl extension is required.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
MessageFormatter::format | Replace named placeholders in an icu message pattern. |
| Related PHP approach | MessageFormatter::formatMessage() is convenient for one-off formatting. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Using an incorrect input or option | Missing arguments or invalid ICU patterns may produce false; do not concatenate false as a successful message. |
| Confusing this API with a related operation | MessageFormatter::formatMessage() is convenient for one-off formatting. |
| Assuming output is identical across environments | Check return values and required extensions or versions. The intl extension is required. |
Key Takeaways
- MessageFormatter::format helps you replace named placeholders in an ICU message pattern.
- Placeholders can be named and can apply number or plural formatting rules.
- Missing arguments or invalid ICU patterns may produce false; do not concatenate false as a successful message.
Use MessageFormatter::format when you need to replace named placeholders in an ICU message pattern. Start with the first example, compare the second, and adapt the practical example to your inputs. Confirm the return value and environment requirements before adding it to production code.