Return the single-value argument or the first multi-value argument with the given name.
See {@link Input::isArgument()} for the definition of "argument".

@param  string $name

@return string|null - argument value or NULL if the argument was not specified
439324
public function getArgument($name) {
        if (!$this->docoptResult)
            return null;

        if ($this->isArgument($name)) {
            $value = $this->docoptResult[$name];
            if (is_array($value))
                return $value ? $value[0] : null;
            return $value;
        }
        return null;
    }
1102163
public function get($name)
    {
        if (!array_key_exists($name, $this->options)) {
            throw new \InvalidArgumentException(sprintf('The option "%s" does not exist.', $name));
        }

        return $this->options[$name];
    }
523588
public function getGet($name = null)
    {
        if ($name !== null) {
            return isset($this->getParams[$name]) ? $this->getParams[$name] : null;
        }

        return $this->getParams;
    }
1197708
public function getArgument($name)
    {
        $offset = array_search($name, $this->argNames, true);
        if ($offset === false || !isset($this->args[$offset])) {
            return null;
        }

        return $this->args[$offset];
    }
547880
public function getFirstTag($name)
    {
        foreach ($this->tags as $i => $tag) {
            if (strtolower($tag->getName()) == $name) {
                return $this->tags[$i];
            }
        }

        return null;
    }
758647
public function getParameter($name): ?Parameter
    {
        /** @var Parameter $parameter */
        foreach ($this->parameters as $parameter) {
            if ($parameter->getKey() === $name) {
                return $parameter;
            }
        }

        return null;
    }
626438
public function getAttribute($name)
    {
        if (!count($this)) {
            throw new \InvalidArgumentException('The current node list is empty.');
        }
        $node = $this->getNode(0);
        return $node->hasAttribute($name) ? $node->getAttribute($name) : null;
    }
840717
protected function doGet(string $name)
    {
        return isset($this->values[$name]) ? $this->values[$name] : null;
    }
758187
public function getNamedRoute($name)
    {
        $this->getNamedRoutes();
        if ($this->hasNamedRoute($name)) {
            return $this->namedRoutes[(string) $name];
        } else {
            return null;
        }
    }
1000099
public static function lookupByName($name)
    {
        if (empty($name)) {
            throw new \InvalidArgumentException('Argument "name" cannot be empty');
        }

        if (!isset(self::$methods_config[$name])) {
            throw new \InvalidArgumentException('Method "' . $name . '" doesn\'t exist');
        }

        return self::$methods_config[$name];
    }
1364694
public function getOption($name)
    {
        if (!array_key_exists($name, $this->commandOptions)) {
            return null;
        }

        $option = $this->commandOptions[$name];

        if ($option->hasBeenProvided() && $option->getProvidedValue() === null && $option->getDefaultValue() === null) {
            return true;
        }

        return $option->getValue();
    }
1298651
public static function get($name)
	{
		$args = func_get_args();
		if (!empty($args))
		{
			unset($args[0]);
		}
		if (isset(self::$list[$name]))
		{
			array_unshift($args, self::$list[$name]);
			return call_user_func_array('sprintf', $args);
		}
		else
		{
			return $name;
		}
	}
112590
public function getOption($name) {
        if (!$this->definition->hasOption($name)) {
            throw new \InvalidArgumentException(sprintf('The "%s" option does not exist.', $name));
        }

        return isset($this->options[$name]) ? $this->options[$name] : $this->definition->getOption($name)->getDefault();
    }
549722
public function getValue($name)
    {
        return (isset($this->options['params'][$name])) ? $this->options['params'][$name] : null;
    }
967077
public function name($name = null)
    {
        if (func_num_args() === 0) {
            return $this->_data['name'];
        }
        $name = (string) $name;
        return $this->_data['name'] = $name;
    }
887329
public function getParam($name)
    {
        $name = strtoupper($name);
        if (isset($_SERVER[$name])) {
            return $_SERVER[$name];
        }
        return null;
    }
608048
public function getArgument($name)
    {
        if (!isset($this->arguments[$name])) {
            throw new OutOfBoundsException(sprintf(
                'The argument "%s" does not exist.',
                $name
            ));
        }

        return $this->arguments[$name];
    }