Java for loop type long not supported [duplicate]

问题

I was trying to do some Project Euler question which involves pandigital numbers with special divisibility requirements of the first 5 prime numbers, and thought that this would be the starting point (see, 1023456789 is the first number being looked at, and 9876543210 is the last one).

    import java.util.*;
    public class pandigital_special 
    {
        public static void main (String args[])
        {
            for (long l = 1023456789; l <= 9876543210; l++)
            {

            }
        }
    }

Can anyone tell me why the compiler claims that for loops only support integers? I have never heard of that. That is to say, the compiler says "The literal 9876543210 of type int is out of range".

回答1:

Your code works fine. The only problem is that your second number (9876543210) is out of the int range, but you are using an int literal.

To use a long literal, simply append an L to the end of the number:

9876543210L

Here is a more complete example:

public class Test {
    public static void main(String[] args){
        for (long l = 1023456789L; l <= 9876543210L; l++){
            System.out.println(l);
        }
    }
}

回答2:

in your for loop

for (long l = 1023456789; l <= 9876543210; l++)

you have number 9876543210 which is too large for int change it to

9876543210L

updated code will look like this

for (long l = 1023456789; l <= 9876543210L; l++)

回答3:

I think you have to have an L after to declare it as a long, like this:

long l = 1023456789L

来源：https://stackoverflow.com/questions/25999966/java-for-loop-type-long-not-supported

标签

java

for-loop

syntax-error

long-integer