The difference between dynamic, VaR and object in fluent

dynamic

•  dynamic d = "CSDN";

• stay Runtime By the system according to the assignment Automatically Infer the data type of the variable
• Dynamic data type , Data types can be changed at run time ：

 dynamic d = "CSDN";
 d = 111;

• At compile time, the Dart The static syntax check of the language is invalid （ For example, call a method that does not belong to the string object , No mistake. ）, But it will be wrong when running .

var

• var v = "CSDN";

• stay Runtime By the system according to the assignment Automatically Infer the data type of the variable .
• var After determining the data type of （ difference dynamic）, Non modifiable .

Object

• Object o1 = 1; 
  Object o2 = "CSDN";

• Object Is the base class for all objects , You can assign a subclass type value to it , As shown in the previous line
• Object The data type of is certain （ difference dynamic）, Non modifiable .
• Object The methods defined in are as follows ：

class Object {

  const Object();

  external bool operator ==(other);

  external int get hashCode;

  external String toString();

  @pragma("vm:entry-point")
  external dynamic noSuchMethod(Invocation invocation);

  external Type get runtimeType;
}