I have a string which stores a number. Now i want to parse that string and get as float.
import java.util.*;
import java.lang.*;
import java.io.*;
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
public static void main (String[] args) throws java.lang.Exception
{
try {
System.out.println(Integer.parseInt(" 2 "));
} catch(NumberFormatException e) {
System.out.println("Exception caught");
}
System.out.println(Float.parseFloat(" 2.4 "));
}
}
Now in the above code if you run it it will be successfull. My QUESTION is this why does trailing spaces in case of integer throws a NumberFormatException
while parsing a float doesnt throw one ?
PS: Same is the case with booolean and double parsing.
PPS: Why is there an inconsistency in java ? And i already check the source code
As you can see in the related source code, the value will be trimmed:
static FloatingDecimal.ASCIIToBinaryConverter readJavaFormatString(String arg) throws NumberFormatException {
boolean arg0 = false;
boolean arg1 = false;
try {
arg = arg.trim();
....
So the blanks will be removed before converting to a floatValue.
For more informations see the sourcecode of FloatingDecimal which is called by Float.class
.
Integer.parseInt()
do not trimm the string value:
public static int parseInt(String arg, int arg0) throws NumberFormatException {
if (arg == null) {
throw new NumberFormatException("null");
} else if (arg0 < 2) {
throw new NumberFormatException("radix " + arg0 + " less than Character.MIN_RADIX");
} else if (arg0 > 36) {
throw new NumberFormatException("radix " + arg0 + " greater than Character.MAX_RADIX");
} else {
int arg1 = 0;
boolean arg2 = false;
int arg3 = 0;
int arg4 = arg.length();
int arg5 = -2147483647;
if (arg4 > 0) {
char arg8 = arg.charAt(0);
if (arg8 < 48) {
if (arg8 == 45) {
arg2 = true;
arg5 = MIN_VALUE;
} else if (arg8 != 43) {
throw NumberFormatException.forInputString(arg);
}
if (arg4 == 1) {
throw NumberFormatException.forInputString(arg);
}
++arg3;
}
int arg7;
for (int arg6 = arg5 / arg0; arg3 < arg4; arg1 -= arg7) {
arg7 = Character.digit(arg.charAt(arg3++), arg0);
if (arg7 < 0) {
throw NumberFormatException.forInputString(arg);
}
if (arg1 < arg6) {
throw NumberFormatException.forInputString(arg);
}
arg1 *= arg0;
if (arg1 < arg5 + arg7) {
throw NumberFormatException.forInputString(arg);
}
}
return arg2 ? arg1 : -arg1;
} else {
throw NumberFormatException.forInputString(arg);
}
}
}
Thats why you get an Exception there