java - 子串与循环

在下面的代码中，我试图基于开始和结束索引来做子字符串，但是在字符串的末尾。系统抛出ArrayIndexOutOfBoundsException。请让我知道如何解决此问题。

    /**
     * @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;
            }
    }

问候，

混沌

最佳答案

逐步调试代码：


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.
s.length()/initlength = 4.
第一个子字符串为0到20。
start = 21和initlenght = 40
第二次循环
s.length()/initlength = 2
子串从21到40。
start = 41和initlength = 80。
第三次循环。
s.length()/initlength = 1和i等于2，因此循环将中断并且程序执行将结束。




根据您的编辑。现在它将循环5次。并且在第三次start = 81和initlength = 160超出字符串范围之后。一直以来total = 5。



如果您希望获得剩余部分，请尝试以下操作：

    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