Helper Functions
****************

.[perex]
[api:Nette\Utils\Helpers] is a static class containing useful helper functions.


Installation:

```shell
composer require nette/utils
```

All examples assume the following class alias is defined:

```php
use Nette\Utils\Helpers;
```


capture(callable $cb): string .[method]
---------------------------------------

Executes a callback and returns the captured output as a string.

```php
$res = Helpers::capture(function () use ($template) {
	$template->render();
});
```


clamp(int|float $value, int|float $min, int|float $max): int|float .[method]
----------------------------------------------------------------------------

Clamps a value within the inclusive range specified by min and max.

```php
Helpers::clamp($level, 0, 255);
```


compare(mixed $left, string $operator, mixed $right): bool .[method]
--------------------------------------------------------------------

Compares two values the same way PHP does. It supports the operators `>`, `>=`, `<`, `<=`, `=`, `==`, `===`, `!=`, `!==`, `<>`. The function is useful in situations where the operator is determined dynamically (is a variable).

```php
Helpers::compare(10, '<', 20); // true
```


falseToNull(mixed $value): mixed .[method]
------------------------------------------

Converts `false` to `null`; other values remain unchanged.

```php
Helpers::falseToNull(false); // null
Helpers::falseToNull(123);   // 123
```


getLastError(): string .[method]
--------------------------------

Returns the last occurred PHP error or an empty string if no error occurred. Unlike `error_get_last()`, it's not affected by the PHP directive `html_errors` and always returns text, not HTML.

```php
Helpers::getLastError();
```


getSuggestion(string[] $possibilities, string $value): ?string .[method]
------------------------------------------------------------------------

From the given `$possibilities`, it finds the string most similar to `$value`, but not identical. It only supports 8-bit encodings.

This is useful when a certain option is invalid, and you want to suggest a similar alternative to the user (but a different one, hence why identical strings are ignored). This is how Nette generates the "did you mean ...?" messages.

```php
$items = ['foo', 'bar', 'baz'];
Helpers::getSuggestion($items, 'fo');   // 'foo'
Helpers::getSuggestion($items, 'barr'); // 'bar'
Helpers::getSuggestion($items, 'baz');  // 'bar', not 'baz'
```