What causes "Array value for key [%s] must be a float, %s found." in laravel/framework?

Pass a float default: Arr::float($data, 'price', 0.0).

laravel/framework · error · InvalidArgumentException

Array value for key [%s] must be a float, %s found.

Error message

Array value for key [%s] must be a float, %s found.

What it means

Thrown by Arr::float() when the value resolved via Arr::get() fails is_float(). Note this accessor does NOT coerce numeric strings (unlike the cache equivalent), so the string '3.14' or an int 3 will fail.

Source

Thrown at src/Illuminate/Collections/Arr.php:401

                    $result[] = $value;
                }
            }
        }

        return $result;
    }

    /**
     * Get a float item from an array using "dot" notation.
     *
     * @throws \InvalidArgumentException
     */
    public static function float(ArrayAccess|array $array, string|int|null $key, ?float $default = null): float
    {
        $value = Arr::get($array, $key, $default);

        if (! is_float($value)) {
            throw new InvalidArgumentException(
                sprintf('Array value for key [%s] must be a float, %s found.', $key, gettype($value))
            );
        }

        return $value;
    }

    /**
     * Remove one or many array items from a given array using "dot" notation.
     *
     * @param  array  $array
     * @param  array|string|int|float  $keys
     * @return void
     */
    public static function forget(&$array, $keys)
    {
        $original = &$array;

View on GitHub (pinned to bd6b5437e6)

Solutions

Pass a float default: Arr::float($data, 'price', 0.0).
Cast the source value to float before it lands in the array.
Use Arr::get() + (float) cast if you want numeric-string coercion.
Fix the dot path so it points at a real float node.

Example fix

// before
$price = Arr::float($order, 'totals.grand');

// after
$price = Arr::float($order, 'totals.grand', 0.0);
// or coerce
$price = (float) Arr::get($order, 'totals.grand', 0);

Defensive patterns

Strategy: type-guard

Validate before calling

$value = Arr::get($data, 'price');
if (! is_float($value)) {
    $value = (float) $value;
}

Type guard

function arrayKeyIsFloat(array $array, string $key): bool {
    return is_float(Arr::get($array, $key));
}

Try / catch

try {
    $price = Arr::float($order, 'totals.grand', 0.0);
} catch (\InvalidArgumentException $e) {
    $price = (float) Arr::get($order, 'totals.grand', 0);
}

Prevention

Arr::float() does not coerce — cast numeric strings to float before reading.
Pass a float default to Arr::float().
Decode JSON with appropriate flags so numbers stay numeric.

When it happens

Trigger: Calling Arr::float($data, 'price') when the value is an int, a numeric string like '3.14', an array, or null (missing key, no float default).

Common situations: JSON decoded payload where prices come through as strings; reading a value stored as int cents; a config key that is sometimes null.

Related errors

AI-assisted analysis of laravel/framework@bd6b5437e6 (2026-08-06). Data as JSON: /data/errors/657df64d9acab55b.json. Report an issue: GitHub.