由于 Java 中涉及表达式运算时的类型自动提升

[Bol5261]

import java.math.BigInteger;

public class S_Sum {
    public static void main(String[] args){
        int a=Integer.MAX_VALUE;
        int b=Integer.MAX_VALUE;
        int c=Integer.MIN_VALUE;
        int d=Integer.MIN_VALUE;
        int sum=a+b;
        int sum2=c+d;
        long sum3=a+b;
        System.out.println("a="+a+",b="+b);
        System.out.println("sum="+sum+",sum2="+sum2+",sum3="+sum3);
    }
}


a=2147483647,b=2147483647
sum=-2,sum2=0,sum3=-2

Process finished with exit code 0