带循环的子串

Question

在下面的代码中，我试图根据开始和结束索引来做子串，但是在字符串的末尾。系统正在抛出ArrayIndexOutOfBoundsException。请告诉我，如何解决此问题。

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        int initlength = 20;
        int start = 0;
        String s = "Some people confuse acceptance with apathy, but there's all "+
"the difference in the world";
        int total=(int)Math.ceil((double)s.length()/(double)initlength);
        for (int i = 0; i < total; i++) {
            System.out.println("s length" + s.substring(start, initlength));
            start = initlength + 1;
            initlength = initlength + initlength;
            }
    }

此致

chaitu

Answer 1

逐步调试代码：

1. 第一次变量

   start=0; initlength=0; s="Some people confuse acceptance with apathy, but there's all the difference in the world"; total = 5.

2. s.length()/initlength = 4.

3. 第一个子字符串将是0到20。
4. start = 21和initlenght = 40
5. 第二次循环
6. s.length()/initlength = 2
7. 子串从21到40。
8. start = 41和initlength = 80。
9. 第三次循环。
10. s.length()/initlength = 1和i等于2因此循环将中断，程序执行将完成。

---

根据您的修改。现在它将循环5次。在第3次start = 81和initlength = 160超出字符串范围之后。始终total = 5。

---

如果你想要它将获得剩下的部分，试试这个：

    int initlength = 20;
    int start = 0;
    String s = "Some people confuse acceptance with apathy, but there's all "
            + "the difference in the world";
    int total = (int) Math.ceil((double) s.length() / (double) initlength);
    for (int i = 0; i < total; i++) {
        if(initlength<s.length()){
            System.out.println("s length" + s.substring(start, initlength));
            start = initlength + 1;
            initlength = initlength + initlength;
        } else {
            initlength = s.length();
            System.out.println("s length" + s.substring(start, initlength));
            break;
        }
    }

输出： -

s lengthSome people confuse 
s lengthcceptance with apat
s lengthy, but there's all the difference in th
s length world

Answer 2

initlength是不是会越来越大，直到超过字符串的末尾？