How to do arithmetic using large numbers in variables in java without getting a exception

Question

Im supposed to write a program that takes in a number and checks if it can be accommodated in a certain datatype or not. Here's a snippet:

try {
   long x=sc.nextLong();
   System.out.println(x+" can be fitted in:");
   if(x>=-128 && x<=127) {
      System.out.println("* byte");
   }
   else if(x>=-32768 && x<=32768) {
      System.out.println("*short");
   }
   else if(x>= −2147483648l && x<= +2147483647L) {
      System.out.println("*int");
   }
   else if(x>=-9223372036854775808l && x<= +9223372036854775807l) {
      System.out.println("*long");
   }
} catch(Exception e) {
   System.out.println(sc.next()+" can't be fitted anywhere.");
}

When I compile this code, a weird error is creeping up.

Solution.java:30: error: illegal character: \8722
else if(x>= −2147483648l && x<= +2147483647L)
^
Solution.java:30: error: not a statement
else if(x>= −2147483648l && x<= +2147483647L)
^
Solution.java:30: error: ';' expected
else if(x>= −2147483648l && x<= +2147483647L)
^
Solution.java:34: error: 'else' without 'if'
   else if(x>=-9223372036854775808l && x<= +9223372036854775807l)

Possible duplicate of [Large Numbers in Java](https://stackoverflow.com/questions/849813/large-numbers-in-java) — azurefrog, Sep 23 '19 at 18:15
You should consider using `Integer.MIN_VALUE` and `Integer.MAX_VALUE` and `Short.MIN_VALUE` etc.... it will really help clean this up — RobOhRob, Sep 23 '19 at 18:17
@azurefrog I don't get you, what is a duplicate of large numbers? — Xenon_Recon, Sep 23 '19 at 18:17
Your question is asking how to handle numbers that cannot be handled by the primitive types in Java. It is a duplication of the linked question, which asks more-or-less the same thing, and has the same answer: Use the arbitrary precision `BigInteger` class to do it. — azurefrog, Sep 23 '19 at 18:19
@RobOhRob is there anything like a Long.MAX_VALUE? Also, is MIN_VALUE an attribute or a method of Short class? — Xenon_Recon, Sep 23 '19 at 18:21
Yup there is a `Long.MAX_VALUE` and a `Short.MIN_VALUE`... You can expect a MAX_VALUE and MIN_VALUE on all these wrappers — RobOhRob, Sep 23 '19 at 18:22
You're getting a compiler error, not an exception. Exceptions may occur during the execution of the program. — rgettman, Sep 23 '19 at 18:31
Also: use `L` in preference to `l` as the long literal suffix (`l` looks a lot like a `1` in certain fonts). — Andy Turner, Sep 23 '19 at 18:39
@azurefrog no ihave to use && itself, other wise even 1024 (which is out of byte size) is greater than -128, which will end up with the program printing that 1024 can be fitted in byte — Xenon_Recon, Sep 23 '19 at 19:12

score 3 · Accepted Answer · answered Sep 23 '19 at 18:19

3

The '−' character you have used for −2147483648l is not a valid character, compare it to the other negetives -32768 or -9223372036854775808l. Thats the compile error.

answered Sep 23 '19 at 18:19

Martin'sRun

522
3
11

rgettman · Answer 2 · 2019-09-23T18:26:07.710

After copying your code, I duplicated the error. It doesn't seem like there's a problem; that character looks like a normal hyphen, but it's not. It's a Unicode "minus sign", which is ironically not recognized as a unary minus operator.

else if(x>= −2147483648l && x<= +2147483647L)
            ^

You can see the difference visually:

System.out.println((int) '−');    // Unicode minus sign, U+2212, error in code
System.out.println((int) '-');    // Ordinary hyphen, works in code

Output:

8722        // Decimal of 0x2212
45

It's possible you copied this Unicode minus sign from another document. Replace it with a normal hyphen and it'll work.

How to do arithmetic using large numbers in variables in java without getting a exception

2 Answers2