java中String类型转换方法

java中String类型转换方法

integer to String :

int i = 42;

String str = Integer.toString(i);

or

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();

or

int i = Integer.parseInt(str);

String to double :

double d = Double.valueOf(str).doubleValue();

String to long :

long l = Long.valueOf(str).longValue();

or

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);

or

String hexstr = Integer.toHexString(i);

hexadecimal (String) to integer :

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

or

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

ASCII code to i = 64;

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

integer to ASCII code c = 'A';

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

To extract Ascii codes from a 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 =

note :

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

i = Integer.parseInt(aString);

}

catch(NumberFormatException e)

{

}