1980:C
printf( "%10.2f"、x);
1988:C ++
cout << setw(10)<< setprecision(2)<< showpoint << x;
1996:Java
java.text.NumberFormat formatter = java.text.NumberFormat.getNumberInstance();
formatter.setMinimumFractionDigits(2);
formatter.setMaximumFractionDigits(2);
文字列s = formatter.format(x); for(int i = s.length(); i <10; i ++)System.out.print( ''); System.out.print(s);
2004:Java
System.out.printf( "%10.2f"、x);