Java2 参考大全(第4版中文版).rar

/* * Created on 2003/12/16 * * To change the template for this generated file go to * Window&gt;Preferences&gt;Java&gt;Code Generation&gt;Code and Comments */ /** * @author zhaoz * * To change the template for this generated type comment go to * Window&gt;Preferences&gt;Java&gt;Code Generation&gt;Code and Comments */ public class area { public static void main(String args[]){ double pi,r,a,c,d; r=10.8; pi=3.1416; a=pi*r*r; c=3.0; d=4.0; System.out.println("area of circle: " + a); char ch1,ch2; ch1=88; ch2='Y'; System.out.println("ch1 and ch2 " + ch1 + " " + ch2); ch1='X'; System.out.println("ch1 " + ch1); ch1++; System.out.println("ch1 now " + ch1); ch1='\123'; System.out.println("ch1 now " + ch1); ch1='\u3540'; System.out.println("ch1 now " + ch1); ch1='\r'; System.out.println("ch1 now " + ch1); ch1='\t'; System.out.println("ch1 now " + (int)ch1); ch1='\b'; System.out.println("ch1 now " + (int)ch1); ch1='\f'; System.out.println("ch1 now " + (int)ch1); a=Math.sqrt(c*c+d*d); System.out.println("a now " + a); int e=257; byte f; f=(byte)e; System.out.println("f now " + f); e=10000%256; System.out.println("e now " + e); f=(byte)pi; System.out.println("pi now " + f); byte aa,bb,cc; aa=125; bb=125; cc=100; e=aa*bb*cc; System.out.println("e now " + e); aa=50; aa=(byte)(aa*2); System.out.println("aa now " + aa); int[][] twoD; twoD=new int[4][]; for(int i=0;i<4;i++){ twoD[i]=new int[i+1]; } int i,j,k=1; for(i=0;i<4;i++){ for(j=0;j<i+1;j++){ twoD[i][j]=k; k++; } } for(i=0;i<4;i++){ for(j=0;j<i+1;j++){ System.out.print(twoD[i][j] + " "); } System.out.println(); } } }