src/EnvConfig.php
public function has(string $key) : bool
    {
        $k = $this->keyConvert($key);
        return getenv($k) !== false;
    }
public function has(string $key) : bool
    {
        $k = $this->keyConvert($key);
        return getenv($k) !== false;
    }
public function has ( string $ key ) : bool { $ k = $ this -> keyConvert ( $ key ) ; return getenv ( $ k ) !== false ; }
Check if an environment var is set.

@param string $key

@return bool

@throws InvalidArgumentException
Propagated.
Check if an environment var is set .