MetricFormatter

The MetricFormatter promotes metric length values between mm, cm, m, and km.

• Non-numeric input is returned unchanged.
• Promotion is based on magnitude.
• Output uses symbols only (no spaces), e.g. 1km, 10cm.

Usage

use Respect\StringFormatter\MetricFormatter;

$formatter = new MetricFormatter('m');

echo $formatter->format('1000');
// Outputs: 1km

echo $formatter->format('0.1');
// Outputs: 10cm

API

MetricFormatter::__construct

• __construct(string $unit)

The $unit is the input unit (the unit you are providing values in).

Accepted units: mm, cm, m, km.

format

• format(string $input): string

If the input is numeric, it is promoted to the closest appropriate metric scale and returned with the corresponding symbol.

Behavior

Promotion rule

The formatter chooses a unit where the promoted value is in the range $[1, 1000)$ when possible. If not possible, it uses the smallest (mm) or largest (km) unit as needed.

No rounding

Values are not rounded. Trailing fractional zeros are trimmed:

$formatter = new MetricFormatter('m');

echo $formatter->format('1.23000');
// Outputs: 1.23m