Common operations
Array
// Declaration * Array is also an object, length is an attribute int [] i=newint[5]; int [] i={0,1}; String[] str=newstring[5]; // string array, double quotation marks, distinguished from char character array String [] str={"A", "B"};
//Find the length array at the beginning , the length is determined (just a property, ' \ ' is useless)
Reference: http://www.cnblogs.com/entry-android/p/5539362.html
N=charset.length;
Array of strings
The length does not end with a terminator;
Inherited
Basic operations
// inheritance, only construction methods cannot be inherited Public class extends box{ publicdouble scale ; Public Scalebox (double W,double h,double D,double f) { Super(W*F,H*F,D*F); // Direct use of the box construction method, must be the first line, first constructed to use Scale=F;}
Method overloading
same name, but with different parameters and different definitions
Method Overrides (Overwrite)
Like the name, the return value is the same as the parameter, and in the subclass it is a new subclass of the child class, and the original method of the parent class cannot be used.
OO Pilot Course--java the Knowledge collection of the beginning of the Meng