Gets the parameter or returns null if it does not exists or is empty.

@param parameters
the parameters
@param name
the name
@return the parameter or returns null if it does not exists or is empty.
502117
public static String getParameter(final PageParameters parameters, final String name)
	{
		return getString(parameters.get(name));
	}
683920
Parameter getCreateParameter(String name) {
		if (this.parameters == null)
			this.parameters = new HashMap<String, Parameter>();
		Parameter param = this.parameters.get(name);
		if (param == null) {
			param = new Parameter(name);
			this.parameters.put(name, param);
		}
		return param;
	}
1302792
public MethodNode getMethod(String name, Parameter[] parameters) {
        for (MethodNode method : getMethods(name)) {
            if (parametersEqual(method.getParameters(), parameters)) {
                return method;
            }
        }
        return null;
    }
530334
public TypeName findParameterType(String name) {
		for (Pair<String, TypeName> item : parameters) {
			if (item.value0.equals(name)) {
				return item.value1;
			}
		}
		return null;
	}
222270
public boolean hasParameter(String parameter) {
    if (info == null || info.parameters == null) {
      return false;
    }
    return info.parameters.containsKey(parameter);
  }
42136
public String getParameterValue(String name) throws RepositoryConfigurationException
   {
      String value = getParameterValue(name, null);
      if (value == null)
         throw new RepositoryConfigurationException("Parameter " + name + " not found ");
      return value;
   }
732935
public static <T> T checkNotNull(final String name,
                                     final T parameter) {
        if (parameter == null) {
            throw new IllegalArgumentException("Parameter named '" + name + "' should be not null!");
        }
        return parameter;
    }
1046982
public static KAlignerParameters getByName(String name) {
        KAlignerParameters params = knownParameters.get(name);
        if (params == null)
            return null;
        return params.clone();
    }
539268
public static void empty(String parameter, String name) {
		if (parameter == null || !parameter.isEmpty()) {
			throw new IllegalArgumentException(name + " is null or not empty.");
		}
	}
1031727
public function getParam($name)
        {
            $name = (string) $name;

            if (!array_key_exists($name, $this->_params)) {
                return null;
            }

            return $this->_params[$name];
        }
295663
public static String checkNotEmpty(final String name,
                                       final String parameter) {
        if (parameter == null || parameter.trim().length() == 0) {
            throw new IllegalArgumentException("Parameter named '" + name + "' should be filled!");
        }
        return parameter;
    }
726179
public void removeParameter( String name )
    {
        if (_parameters == null || !_parameters.hasParameters())
            return;

        _parameters.removeParameter(name);
    }
537189
public function param($name = '')
    {
        switch ($this->method) {
            case 'POST':
                $data = $this->post();
                break;
            case 'GET':
                $data = $this->get();
                break;
        }

        if (empty($name)) {
            return $data;
        } else {
            return isset($data[$name]) ? $data[$name] : null;
        }
    }
71772
def getParameterByName(self, name):
        """"""
        result = None
        for parameter in self.getParameters():
            nameParam = parameter.getName()
            if nameParam == name:
                result = parameter
                break
        return result
720865
@Override
    public Object getParameterType(String name) {
        if (name.equals(CHECK_RING_SYSTEM))
            return Boolean.TRUE;
        else
            throw new IllegalArgumentException("No parameter for name: " + name);
    }
408183
protected String getDescription(Parameter parameter) {
        if (parameter.isAnnotationPresent(Desc.class)) {
            Desc annotation = parameter.getAnnotation(Desc.class);
            return translate(annotation.key(), annotation.value());
        }
        return null;
    }
581353
@Override
    public Object getParameterType(String name) {
        if (name.equals("checkAromaticity")) return Boolean.TRUE;
        return null;
    }