基础学习-内存溢出问题

public class Demo3 {
    public static void main(String[] args) {
        // 内存溢出问题
        // JDK7，下划线
        int money = 10_0000_0000;
        int year = 20;
        int total = money * year;   // -1474836480 内存溢出
        System.out.println(total);

        long total2 = money * year;
        System.out.println(total2); // -1474836480 默认int

        long total3 = money * (long)year;   // 20000000000
        System.out.println(total3);
    }
}