has()

Check whether a path exists in the document.

Signature

JsonFast::has(string $json, string $path): bool

Parameters

Name	Type	Description
$json	string	JSON document
$path	string	Dot/bracket path (same rules as get())

Returns

true if the path exists; false otherwise.

Distinguishes “path missing” from “value is JSON null” — unlike relying on get() alone.

Examples

$json = '{"user":{"name":"Allan","optional":null}}';

JsonFast::has($json, 'user.name');      // true
JsonFast::has($json, 'user.optional');  // true (key exists, value is null)
JsonFast::has($json, 'user.missing');   // false

Conditional reads:

if (JsonFast::has($config, 'features.beta')) {
    enableBeta(JsonFast::get($config, 'features.beta'));
}

Related

• get() — read the value
• extract() — batch reads