Double类型输出的问题
double   a   =   2.0; 
 double   b   =   3.0; 
 System.out.println(a/b);   
 此时输出为0.6666666666666666 
 我想让它只输出两个有效为即为0.67,该怎么写呢?
------解决方案--------------------double a = 2.0; 
 double b = 3.0; 
 long num = Math.round((a/b)*100); 
 System.out.println(num/100.0);
------解决方案--------------------NumberFormat nf = NumberFormat.getInstance(); 
 nf.setMaximumFractionDigits(2); 
 System.out.println(nf.format(a/b));