java study 01

Methods

• Defining & Calling Methods
• Inputs & Output of A Method
  e.g.
  1 submitOrder(…){
  calculatePrice(…);
  }
  2 cacalculatePrice(…){_}
  1 to 2 zero or more input parameters（输入参数）
  2 to 1 zero or one return value（返回值）
• Defining a method
  e.g.
  private int calculatePrice(int quantity){ }
  “private” : Access modifer（访问修饰符） Who has access to this method? Private or Public ？
  “int”: Return data type（输出返回数据类型）
  “calculatePrice”: Method name（用动词开头）
  “int”: Parameter data type（输入参数类型）
  “quantity”: Parameter variable name
• Input Parameters
  The inputs passed to a method can be called arguments.（实参）
  NOTE：Parameters refers to the list of variables in a method declaration. Arguments are the actual values that are passed in when the method is invoked. When you invoke a method, the arguments used must match the declaration’s parameters in type and order.
• Return Values
  a.return price;
  b.if you don’t need a return value, build a void return value type, like this :
  private void price(int quantity){
  }
  c.codes are unreachable after return.
  d.specify return data type.
  e.remenber always add comments.
  f.numbers should not be in quotes