Beginner question with check true value???

[vieboi]

Hey guys!!! It's new Java beginner here... really need for help

do you know how to check a String value as Integer value?

For example I set:
String telephoneNum = "47396430854"; // Please note String tyle
then check the incoming telephone number that every digit between 0 to 9 // is it integer value?
If I set telephoneNum = "7462M37R479", the program throw exception.


---> And also the sencond question, check a double value is true of tyle double.

For example If I set the wrong value like
Double = 9999;
then program say the incoming value is not of type double and throw exception.


Sorry about my poor English, but it's only the language I can write here.

 

[lhein]

Hey guys!!! It's new Java beginner here... really need for help

do you know how to check a String value as Integer value?

For example I set:
String telephoneNum = "47396430854"; // Please note String tyle
then check the incoming telephone number that every digit between 0 to 9 // is it integer value?
If I set telephoneNum = "7462M37R479", the program throw exception.


---> And also the sencond question, check a double value is true of tyle double.

For example If I set the wrong value like
Double = 9999;
then program say the incoming value is not of type double and throw exception.


Sorry about my poor English, but it's only the language I can write here.

Hi,

for the first try this:

int i_phoneNr;

try
{
   i_phoneNr = new Integer(s_telephonNum).intValue();
}
catch (NumberFormatException ex)
{
   // if the string can't be cast to Integer, then this exception is thrown, so handle it as you want
   // for my example I only set the phoneNr to zero 
   i_phoneNr = 0;
}

for the second problem:

if I understood you correct then your program throws an error when assigning 9999 to your Double value.
first of all Double is an object and can't be set to a value in this way.
Take double instead like

double d = 9999d;

because double is a primitive datatype like int.
The d behind the number makes the number handled as a double value.

But you can also have this

Double doubl = new Double(9999d);

Hope this helps,

LR

 

[bummerland]

Hey guys!!! It's new Java beginner here... really need for help

do you know how to check a String value as Integer value?

For example I set:
String telephoneNum = "47396430854"; // Please note String tyle
then check the incoming telephone number that every digit between 0 to 9 // is it integer value?
If I set telephoneNum = "7462M37R479", the program throw exception.

int x;
try
{
    x = Integer.parseInt(telephoneNum);
}
catch(NumberFormatException)
{
    //It's no number
}

---> And also the sencond question, check a double value is true of tyle double.

For example If I set the wrong value like
Double = 9999;
then program say the incoming value is not of type double and throw exception.

double d = 9999; //works

 

[lhein]

int x;
try
{
    x = Integer.parseInt(telephoneNum);
}
catch(NumberFormatException ex)
{
    //It's no number
}

now it's perfect

LR