src/Http/Formatting/HttpHeaderParser.php
public function isJson(HttpHeaders $headers): bool
    {
        $contentType = null;
        $headers->tryGetFirst('Content-Type', $contentType);

        return preg_match("/application\/json/i", $contentType) === 1;
    }
public function isJson(HttpHeaders $headers): bool
    {
        $contentType = null;
        $headers->tryGetFirst('Content-Type', $contentType);

        return preg_match("/application\/json/i", $contentType) === 1;
    }
public function isJson ( HttpHeaders $ headers ) : bool { $ contentType = null ; $ headers -> tryGetFirst ( 'Content-Type' , $ contentType ) ; return preg_match ( "/application\/json/i" , $ contentType ) === 1 ; }
Gets whether or not the headers have a JSON content type

@param HttpHeaders $headers The headers to parse
@return bool True if the message has a JSON content type, otherwise false
@throws RuntimeException Thrown if the content type header's hash key could not be calculated
Gets whether or not the headers have a JSON content type