java类型转换

1如何将字串 String 转换成整数 int?

  A. 有两个方法:

  1). int i = Integer.parseInt([String]); 或

  i = Integer.parseInt([String],[int radix]);

  2). int i = Integer.valueOf(my_str).intValue();

  注: 字串转成 Double, Float, Long 的方法大同小异.

  2 如何将整数 int 转换成字串 String ?

  A. 有叁种方法:

  1.) String s = String.valueOf(i);

  2.) String s = Integer.toString(i);

  3.) String s = "" + i;

  注: Double, Float, Long 转成字串的方法大同小异.

 

  这是一个例子,说的是JAVA中数据数型的转换.供大家学习引

  package cn.com.lwkj.erts.reGISter;

  import java.sql.Date;

  public class TypeChange {

  public TypeChange() {

  }

  //change the string type to the int type

  public static int stringToInt(String intstr)

  {

  Integer integer;

  integer = Integer.valueOf(intstr);

  return integer.intValue();

  }

  //change int type to the string type

  public static String intToString(int value)

  {

  Integer integer = new Integer(value);

  return integer.toString();

  }

  //change the string type to the float type

  public static float stringToFloat(String floatstr)

  {

  Float floatee;

  floatee = Float.valueOf(floatstr);

  return floatee.floatValue();

  }

  //change the float type to the string type

  public static String floatToString(float value)

  {

  Float floatee = new Float(value);

  return floatee.toString();

  }

  //change the string type to the sqlDate type

  public static java.sql.Date stringToDate(String dateStr)

  {

  return java.sql.Date.valueOf(dateStr);

  }

  //change the sqlDate type to the string type

  public static String dateToString(java.sql.Date datee)

  {

  return datee.toString();

  }

  public static void main(String[] args)

  {

  java.sql.Date day ;

  day = TypeChange.stringToDate("2003-11-3");

  String strday = TypeChange.dateToString(day);

  System.out.println(strday);

  }

  }

  JAVA中常用数据类型转换函数

  虽然都能在JAVA API中找到,整理一下做个备份。

  string->byte

  Byte static byte parseByte(String s)

  byte->string

  Byte static String toString(byte b)

  char->string

  Character static String to String (char c)

  string->Short

  Short static Short parseShort(String s)

  Short->String

  Short static String toString(Short s)

  String->Integer

  Integer static int parseInt(String s)

  Integer->String

  Integer static String tostring(int i)

  String->Long

  Long static long parseLong(String s)

  Long->String

  Long static String toString(Long i)

  String->Float

  Float static float parseFloat(String s)

  Float->String

  Float static String toString(float f)

  String->Double

  Double static double parseDouble(String s)

  Double->String

  Double static String toString(Double d)

posted @ 2013-12-18 10:19  gscheng  阅读(280)  评论(0编辑  收藏  举报