Verifies if a parameter exists
@param  string $key The parameter name (array key)
@return boolean
194418
public function exists($key)
    {
        // Checks if we need to verify a nested array
        if (preg_match('/\.+/', $key))
        {
            $keys   = explode('.', $key);
            $levels = count($keys);

            // Quick workaround
            if ($levels == 4)
            {
                return isset($this->params[$keys[0]][$keys[1]][$keys[2]][$keys3]);
            }
            else if ($levels == 3)
            {
                return isset($this->params[$keys[0]][$keys[1]][$keys[2]]);
            }
            else
            {
                return isset($this->params[$keys[0]][$keys[1]]);
            }
        }

        // Non-nested array validation
        if (array_key_exists($key, $this->params))
        {
            return true;
        }

        return false;
    }
381311
public function has($key){
        if($this->offsetExists($key) && (bool)$this->offsetGet($key)){
            return TRUE;
        }
        return FALSE;
    }
139665
public function has($key)
    {
        return $this->params->has($key) || $this->payload->has($key);
    }
566699
public function hasKey(string $key): bool
    {
        return $key && strpos($key, '@@') === false && file_exists($this->getPathFromKey($key));
    }
1179362
public function has($key)
    {
        $keys = explode('.', $key);
        $cKeys = count($keys);
        $config = $this->_arr;

        for ($i = 0; $i < $cKeys; ++$i) {
            if (is_array($config)) {
                if (array_key_exists($keys[$i], $config)) {
                    $config = $config[$keys[$i]];
                } else {
                    return false;
                }
            } else {
                return false;
            }
        }

        return true;
    }
679446
public function exists($key)
    {
        $this->init();
        $result = $this->driver->exists($key);
        return (bool)$result;
    }
602663
protected function hasKey($key)
    {
        return ($this->mode == self::MODE_INDEXED && $key == '') || \array_key_exists($key, $this->params);
    }
266238
public function exists(?string $key = null) : bool
    {
        $key = $this->constructKey($key);

        return $this->parseKey($key, function ($part, $result) {
            return array_key_exists($part, $result);
        });
    }
1239417
public function has($key)
    {
        if (!$this->isEnabled()) {
            return false;
        }

        return (false !== apc_fetch($this->prefix() . $key));
    }
1339593
public function has($key = null)
    {
        if ($key === null) {
            return $this->count() > 0;
        }

        $arr = &$this->getStackByReference($key);

        return is_array($arr) ? array_key_exists($key, $arr) : false;
    }
986166
public function hasProperty( $key )
    {
        return \array_key_exists( $key, $this->data ) or in_array( $key, $this->additionalProperties );
    }
684459
public function exists($key) {
		return isset($this->_data[$key]) || isset($this->registered[$key]);
	}
923242
public function offsetExists($key)
    {
        return isset($this->container[$key]) || \array_key_exists($key, $this->container);
    }
165895
public function has($key)
    {
        $keys = is_array($key) ? $key : func_get_args();

        $input = $this->all();

        foreach ($keys as $value) {
            if (! Arr::has($input, $value)) {
                return false;
            }
        }

        return true;
    }
727280
public function has(string $key): bool
    {
        return isset($this->data[$key]) || array_key_exists($key, $this->data);
    }
578242
public function exists($key) {

		if(false === is_string($key) && false === is_array($key)) {
   			return trigger_error(sprintf('Argument 1 passed to %s() must be of the type string or array, "%s" given', __METHOD__, gettype($key)), E_USER_ERROR);
   		}

   		if(0 === strlen($key)) {
   			return trigger_error(sprintf('Argument 1 passed to %s() may not be an empty string', __METHOD__), E_USER_ERROR);
   		}

		return apcu_exists($key);
	}
1349419
public function has($key)
    {
        return isset($this->data[$key]) || array_key_exists($key, $this->data);
    }