Java的整个字符串的结束索引在最后一个字符之外详解编程语言

/** 
 * Created by xfyou on 2016/11/4. 
 */ 
public class SubstringDemo { 
    public static void main(String[] args) { 
        String a = "Java is great."; 
        System.out.println(a); 
        System.out.println(a.substring(5)); 
        System.out.println(a.substring(5, 7)); 
 
        // Java的整个字符串的结束索引在最后一个字符之外 
        System.out.println(a.substring(5, a.length())); 
 
        System.out.println(a.indexOf('.')); 
        System.out.println(a.length()); 
    } 
}