Java 约定 - 使用花括号来隔离代码？

Question

I'm curious about this. I've recently had the idea of isolating segments of code using the curly braces for both visual organization and to isolate the variables to that specific scope (if only to keep them from cluttering the suggestions in Eclipse in larger functions). For instance:

public void startInstall()
{
    boolean success = false;
    m_progress = 0;

    // Determine Chance of Success (This is isolated in curly braces)
    {
        double weight_total = 0;
        double weight_sum = 0;
        for(int i=0; i < Data.m_feature_selection.size(); i++)
        {
            if(Data.m_feature_selection.get(i))
            {
                int weight = Data.m_feature_weight.get(i);
                weight_total += Math.abs(weight);
                weight_sum += weight;
            }
        }
        double succ_chance = (weight_sum / weight_total) + 0.15;
        if(Math.random() <= succ_chance)
            success = true;
    }
    // Do more stuff....
}

Does this affect performance? Is it against convention? Would doing this be frowned upon in a professional environment?

Answer 1

If you need to do that, you should break the block out into a method.

Further, comments are a code smell. In almost every case, if you have to comment your code, it's poorly written:

Turn your comment into a method name!

double determineChanceOfSuccess() {
    double weight_total = 0;
    double weight_sum = 0;
    for(int i=0; i < Data.m_feature_selection.size(); i++) {
        if(Data.m_feature_selection.get(i)) {
            int weight = Data.m_feature_weight.get(i);
            weight_total += Math.abs(weight);
            weight_sum += weight;
        }
    }
    double succ_chance = (weight_sum / weight_total) + 0.15;
    return succ_chance;
}

Now your main code is readable!

public void startInstall() {
    m_progress = 0;

    double succ_chance = determineChanceOfSuccess();

    boolean success = Math.random() <= succ_chance;

    // Do more stuff....
}

Note slight code clean up too.