如何在返回前将double类型的骰子求和结果转换为整数？

Absolutely you can, but there's a critical detail to get right—since dice rolls are always whole numbers (1-6 per die, so sums from 2-12), you’ll want to make sure your conversion doesn’t introduce logic errors. Let’s walk through the best approaches:

The Right Way: Generate Integer Dice Rolls From the Start #

Instead of dealing with double values at all, it’s cleaner and more accurate to convert each die roll to an integer first. This matches the real-world behavior of dice perfectly:

public static int getTotal() {
    // Math.random() * 6 gives a value between 0 (inclusive) and 6 (exclusive)
    // Casting to int truncates the decimal, giving us 0-5; add 1 to get 1-6
    int dice1 = (int) (Math.random() * 6) + 1;
    int dice2 = (int) (Math.random() * 6) + 1;
    // Return the integer sum directly—no extra conversion needed
    return dice1 + dice2;
}

• This approach guarantees you get valid integer values for each die, so the sum will always be a correct whole number.
• Changing the return type to int also makes your code more readable—anyone looking at the method will immediately know it returns a dice sum, not a fractional value.

If You Must Keep the Double Logic (Not Recommended) #

If for some reason you want to keep the double variables for the individual dice, don’t just cast the total sum to int—that can cause bugs. For example:

• If dice1 = 1.9 (which should correspond to a 1) and dice2 = 1.9 (also a 1), their sum is 3.8. Casting that to int gives you 3, but the actual correct sum is 2.

Instead, convert each die to an integer first, then add them:

public static int getTotal() {
    double dice1 = (Math.random() * 6) + 1;
    double dice2 = (Math.random() * 6) + 1;
    // Convert each die to its integer value before summing
    return (int) dice1 + (int) dice2;
}

This works, but it’s redundant—you’re just adding an extra double step when you could generate integers directly.

Why Avoid Casting the Total Sum? #

As the example above shows, the decimal parts of two dice rolls can add up to more than 1. When you cast a double like 3.8 to int, it truncates the decimal and gives you 3—even though the actual sum of the two dice (1 + 1) should be 2. This leads to incorrect results that are hard to spot at first glance.

Final Tip #

Using int from the start is the most straightforward and error-free approach. Your main method will receive a clean integer value, no extra conversion required.

内容的提问来源于stack exchange，提问作者Luke Mihalovich