Programming Methodology(七)

呼终于弄完毕业论文了~在国难日这天恢复更新~

1.      在JAVA中，如果有数据丢失，例如从DOUBLE到INTEGER丢失了小数点后面的数据，则必须加上CAST.

2.      While loop -àindefinite loop  for loop-àdefinite loop  介绍一个 Half anda loop 的小程序：

package DefaultPackage;

 

import acm.program.*;

 

publicclassABetterHalfLoopextends ConsoleProgram {

  privatestaticfinalintSENTINAL = 0;

 

  publicvoid run()

  {

     int total = 0;

     while(true)

     {

         int val = readInt("Enter number:");

         if(val ==SENTINAL)break;

         else total+=val;

     }

     println("The total is "+total+".");

  }

 

}

3.      for VS while

for(init ; test ; step)                                    init;

{                                                while(test)

           Statement;                V.S                  {

}                                                      statement;

                                                                                                                              Step;

                                                  }

4.      Checker Board程序：

  package DefaultPackage;

 

import acm.graphics.*;

import acm.program.*;

 

publicclassCheckerBoardextends GraphicsProgram{

 

  privatestaticfinalintROWS = 8;

  privatestaticfinalintCOLUMNS = 8;

  publicvoid run()

  {

     int SquareSize =getHeight()/ROWS ;

     for(int i = 0; i<ROWS; i++)

     {

         for(int j =0; j<COLUMNS; j++)

         {

            int x = j*SquareSize;

            int y = i*SquareSize;

            GRect sq= new GRect(x,y,SquareSize,SquareSize);

            sq.setFilled((x+y)%2!=0);

            add(sq);

         }

     }

  }

}

5.  Methods.

许多数学相关的函数可以在这个包里找到： java.lang.Math;

PS:MARK一下Apocalyptica乐队