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.

Java数据类型转换 ynniebo [收藏]

关键字 类型转换

出处

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)