I need to parse string hex value to the Integer value. Like this:
String hex = "2A"; //The answer is 42
int intValue = Integer.parseInt(hex, 16);
But when I insert an incorrect hex value (for example "LL") then I get java.lang.NumberFormatException: For input string: "LL" How I can avoid it (for example return 0)?
You can catch the exception and return zero instead.
public static int parseHexInt(String hex) {
try {
return Integer.parseInt(hex, 16);
} catch (NumberFormatException e) {
return 0;
}
}
However, I recommend re-evaluating your approach, as 0 is a valid hex number as well, and doesn't signify invalid input such as "LL".
For input string: "LL" How I can avoid it (for example return 0)?
Just catch the exception and assign zero to intvalue
int intValue;
try {
String hex = "2A"; //The answer is 42
intValue = Integer.parseInt(hex, 16);
}
catch(NumberFormatException ex){
System.out.println("Wrong Input"); // just to be more expressive
invalue=0;
}
intValue outside the try block. Scope matters.Enclose it in a try catch block. That is how Exception Handling works: -
int intValue = 0;
try {
intValue = Integer.parseInt(hex, 16);
} catch (NumberFormatException e) {
System.out.println("Invalid Hex Value");
// intValue will contain 0 only from the default value assignment.
}
Just catch the exception and set the default value. However, you need to declare the variable outside the try block.
int intValue;
try {
intValue = Integer.parseInt(hex, 16);
} catch (NumberFormatException e) {
intValue = 0;
}
If you need to set the value using an initializer expression (say, for a final variable), you'll have to package up the logic in a method:
public int parseHex(String hex) {
try {
return Integer.parseInt(hex, 16);
} catch (NumberFormatException e) {
return 0;
}
}
// elsewhere...
final int intValue = parseHex(hex);
How I can avoid it (for example return 0)
Using a simple method which will return 0 in case a NumberFormatException occurrs
public int getHexValue(String hex){
int result = 0;
try {
result = Integer.parseInt(hex, 16);
} catch (NumberFormatException e) {
e.printStackTrace();
}
return result;
}
