Possible Duplicate:
How to convert string to int in Java?
MY code is supposed to read strings and then take the corresponding actions, but if that string is a line of numbers i need this line as a full number (an int) not as a string anymore.can this be done?
Integer.parseInt(...) for primitive int.
valueOf method.Look at the static method Integer.parseInt(String string). This method is overloaded and is also capable of reading values in other numeral systems than the decimal system. If stringcan't be parsed as Integer, the method throws a NumberFormatException which can be catched as follows:
string = "1234"
try {
int i = Integer.parseInt(string);
} catch (NumberFormatException e) {
System.err.println(string + " is not a number!");
}
In addition to what Dave and wullxz said, you could also user regular expressions to find out if tested string matches your format e.g.
import java.util.regex.Pattern;
...
String value = "23423423";
if(Pattern.matches("^\\d+$", value)) {
return Integer.valueOf(value);
}
Using regular expression you could also recover other type of numbers like doubles e.g.
String value = "23423423.33";
if(Pattern.matches("^\\d+$", value)) {
System.out.println(Integer.valueOf(value));
}
else if(Pattern.matches("^\\d+\\.\\d+$", value)) {
System.out.println(Double.valueOf(value));
}
I hope that will help to solve your problem.
EDIT
Also, as suggested by wullxz, you could use Integer.parseInt(String) instead of Integer.valueOf(String). parseInt returns int whereas valueOf returns Integer instance. From performance point of view parseInt is recommended.
