java 原生数据类型的转换_java数据类型之间的转换

java的基本数据类型：short, int, long, float, double, char,string

对应的包装类型：Short, Integer, Long, Float, Double, Character, String

基本数据类型和String之间的转换：toString()

1. int to string:

String s = Integer.toString(int n);

2. short to string

String s = Short.toString(short n);

3. long to string

String s = Long.toString(Long n);

4. float to string

String s = Float.toString(Float f)

5. double to string

String s = Double.toString(Double n);

String to 基本数据类型：parsexxx(), valueOf()

1. string to int

int n = Integer.parseInt(String s);

int n = Interget.valueOf(String s);

2. String to short

short n = Short.parseShort(String s);

short n = Short.valueOf(String s);

3. String to long

long n = Long.parseLong(String s);

long n = Long.valueOf(String s);

4. String to float

float n = Float.parseFloar(String s);

float f = Float.valueOf(String s);

5. String to double

double d = Double.parseDouble(String s);

double d = Double.valueOf(String s);

char to int:

1. 利用char的Unicode编码规则

char c = '8';

int n = c -48;

2. 用Integer.parseInt()

Character ch = '8';

int n =  Interget.parseInt(c.toString());

int to char:

int n = 8;

char c = (char)(n+48);

package cn.Sandy.Review;

/**

* Hello world!

*

*/

public class App

{

public static void main( String[] args )

{

/**

* String to short/int/long/float/double

*/

String s = "8";

int i = Integer.parseInt(s); //string to int

long l = Long.parseLong(s); //string to long

short sh = Short.parseShort(s); //string to short

float f = Float.parseFloat(s); //string to float

double d = Double.parseDouble(s); //string to double

System.out.println(i);

System.out.println(l);

System.out.println(sh);

System.out.println(f);

System.out.println(d);

/**

* short/int/long/float/double types to string

*/

short sho = 12345;

String sint = Integer.toString(8); // int to string

String sshort = Short.toString(sho); //short to string

String slong = Long.toString(1234562222); //long to string

String sf = Float.toString(3.0f); // float to string

String sd = Double.toString(20.22d); //double to string

System.out.println(sint);

System.out.println(sshort);

System.out.println(slong);

System.out.println(sf);

System.out.println(sd);

/*

* char to int and int to char

*/

int num = 8;

char ch1 = (char)(num + 48); //利用char的unicode编码

System.out.println(ch1);

Character ch2 = '8';//char是基本的数据类型， Character是包装类型

int mun1 = Integer.parseInt(ch2.toString());

System.out.println(ch2);

}

}