AppendStringTest.java

public class AppendStringTest {
    public static void main(String[] args) {
        String text = "";

        long beginTime = System.currentTimeMillis();
        for(int i = 0; i < 10000; i++)
            text = text + i;
        long endTime = System.currentTimeMillis();
        System.out.println("執行時間：" + (endTime - beginTime));

        StringBuilder builder = new StringBuilder("");
        beginTime = System.currentTimeMillis();
        for(int i = 0; i < 10000; i++)
            builder.append(String.valueOf(i));
        endTime = System.currentTimeMillis();
        System.out.println("執行時間：" + (endTime - beginTime));
    }
}