Java/Data Type/Convert to String
Содержание
- 1 Convert a byte array to a Hex string
- 2 Convert an int value to String: concatenate string to an int value
- 3 Convert an int value to String: Integer.toString(i)
- 4 Convert an int value to String: new Integer(i).toString()
- 5 Convert from integer to String
- 6 The Value of a String with String.valueOf method
- 7 To catch illegal number conversion, try using the try/catch mechanism.
- 8 Use toString method of Integer class to conver Integer into String.
Convert a byte array to a Hex string
<source lang="java">
public class Main {
public static void main(String[] argv) {
byte[] b = "ada".getBytes();
for (int i = 0; i < b.length; i++) {
System.out.println(Integer.toString((b[i] & 0xff) + 0x100, 16).substring(1));
}
}
} /* 61 64 61
- /
</source>
Convert an int value to String: concatenate string to an int value
<source lang="java">
public class Main {
public static void main(String[] args) {
int i = 50;
String str = "" + i;
System.out.println(str + " : " + ("" + i).getClass());
}
} // 50 : class java.lang.String
</source>
Convert an int value to String: Integer.toString(i)
<source lang="java">
public class Main {
public static void main(String[] args) {
int i = 50;
String str = Integer.toString(i);
System.out.println(str + " : " + Integer.toString(i).getClass());
}
} //50 : class java.lang.String
</source>
Convert an int value to String: new Integer(i).toString()
<source lang="java">
public class Main {
public static void main(String[] args) {
int i = 50;
String str = new Integer(i).toString();
System.out.println(str + " : " + new Integer(i).toString().getClass());
}
} //50 : class java.lang.String
</source>
Convert from integer to String
<source lang="java">
public class Main {
public static void main(String[] args) throws Exception {
int i = 2;
String str = Integer.toString(i);
System.out.println(str);
// or
str = "" + i;
System.out.println(str);
}
}
</source>
The Value of a String with String.valueOf method
<source lang="java">
class MainClass {
public static void main(String[] args) {
String s = String.valueOf(false);
System.out.println(s);
s = String.valueOf("A");
System.out.println(s);
char[] c = { "a", "b", "c" };
s = String.valueOf(c);
System.out.println(s);
s = String.valueOf(c, 0, 2);
System.out.println(s);
s = String.valueOf(3.5d);
System.out.println(s);
s = String.valueOf(2.5f);
System.out.println(s);
s = String.valueOf(59);
System.out.println(s);
s = String.valueOf(8000l);
System.out.println(s);
}
}
</source>
To catch illegal number conversion, try using the try/catch mechanism.
<source lang="java">
public class Main {
public static void main(String[] args) throws Exception {
try {
int i = Integer.parseInt("asdf");
} catch (NumberFormatException e) {
;
}
}
}
</source>
Use toString method of Integer class to conver Integer into String.
<source lang="java">
public class Main {
public static void main(String[] args) {
Integer intObj = new Integer(10);
String str = intObj.toString();
System.out.println("Integer converted to String as " + str);
}
}
</source>
