####1、int、float、double 转string
int i;
(1)String s = String.valueOf(i);
(2) String s = Integer.toString(i);
(3) String s = "" + i;####2）String转int、float、double
String str = "123";
(1) int i = Integer.parseInt(str);
(2) int i = Integer.valueOf(str).intValue();####3)float 、double 转 int
float a = 12.123;
int b = (int) a;####4)float 、double 保留小数点后几位
float mfloat = 12.12345;
DecimalFormat fnum = new DecimalFormat("##0.00");
String strfloat = fnum.format(mfloat);
//或者
//String strfloat = new DecimalFormat("0.00").format(mfloat);
