JAVA类型转换大全-白红宇

Java自带的库很多用起来都不是那么方便，类型转换很多都要显示去做真的有点难记住。找了篇资料说的很详细，记录下来吧。

integer to String : int i = 42;

String str = Integer.toString(i);

String str = "" + i

double to String : String str = Double.toString(i);

long to String : String str = Long.toString(l);

float to String : String str = Float.toString(f);

String to integer : str = "25";

int i = Integer.valueOf(str).intValue();

int i = Integer.parseInt(str);

String to double : double d = Double.valueOf(str).doubleValue();

String to long : long l = Long.valueOf(str).longValue();

long l = Long.parseLong(str);

String to float : float f = Float.valueOf(str).floatValue();

decimal to binary : int i = 42;

String binstr = Integer.toBinaryString(i);

decimal to hexadecimal : int i = 42;

String hexstr = Integer.toString(i, 16);

String hexstr = Integer.toHexString(i);

hexadecimal (String) to integer : int i = Integer.valueOf("B8DA3", 16).intValue();

int i = Integer.parseInt("B8DA3", 16);

ASCII code to String int i = 64;

String aChar = new Character((char)i).toString();

integer to ASCII code (byte) char c = 'A';

int i = (int) c; // i will have the value 65 decimal

To extract Ascii codes from a String String test = "ABCD";

for ( int i = 0; i < test.length(); ++i ) {

char c = test.charAt( i );

int i = (int) c;

System.out.println(i);

}

integer to boolean b = (i != 0);

boolean to integer i = (b)?1:0;

note :To catch illegal number conversion, try using the try/catch mechanism.

try{

i = Integer.parseInt(aString);

}catch(NumberFormatException e){

}

本文转自passover 51CTO博客，原文链接：http://blog.51cto.com/passover/425915，如需转载请自行联系原作者