Result · Sentiment Analysis for PHP

use Risan\Sentiment\Result;

final readonly class Result implements JsonSerializable is what Sentiment::analyze() and Analyzer::analyze() return. Its properties are read-only, so a result can be passed around and cached safely. You normally never construct one yourself.

$result = Sentiment::analyze('VADER is smart, handsome, and funny.');

$result->label;    // Label::Positive
$result->compound; // 0.8316
$result->positive; // 0.746
$result->negative; // 0.0
$result->neutral;  // 0.254

Properties

Property	Type	Range	Description
`$label`	`Label`		The verdict, derived from `compound` and the analyzer’s threshold.
`$compound`	`float`	-1 to 1	Overall score, rounded to 4 decimals. Negative means negative sentiment.
`$positive`	`float`	0 to 1	Share of positive signal, rounded to 3 decimals.
`$negative`	`float`	0 to 1	Share of negative signal, rounded to 3 decimals.
`$neutral`	`float`	0 to 1	Share of neutral content, rounded to 3 decimals.

positive, negative and neutral add up to about 1. Empty text gives 0.0 for the compound and all three ratios. See Understanding the scores.

Methods

isPositive()

public function isPositive(): bool

True when $label is Label::Positive.

isNegative()

public function isNegative(): bool

True when $label is Label::Negative.

isNeutral()

public function isNeutral(): bool

True when $label is Label::Neutral.

$result = Sentiment::analyze('VADER is smart, handsome, and funny.');

$result->isPositive(); // true
$result->isNegative(); // false
$result->isNeutral();  // false

toArray()

public function toArray(): array

Returns the result as a plain array. The label is its string value.

$result->toArray();
// [
//     'label' => 'positive',
//     'compound' => 0.8316,
//     'positive' => 0.746,
//     'negative' => 0.0,
//     'neutral' => 0.254,
// ]

jsonSerialize()

public function jsonSerialize(): array

Called by json_encode(). It returns the same shape as toArray(), so you can encode a result directly.

echo json_encode($result);
// {"label":"positive","compound":0.8316,"positive":0.746,"negative":0,"neutral":0.254}

PHP drops the trailing .0 of whole floats in JSON, so 0.0 is encoded as 0. Pass JSON_PRESERVE_ZERO_FRACTION if you want 0.0.