为什么会出现这个异常?
逍遥自在” 2019-08-08 10:25:05
Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 9
public class test {
public static void main(String [] args)
{
String str = "HelloWorld";
StringBuffer buffer = new StringBuffer();
for(int i=str.length()-1; i>=0; i--)
{
char b = str.charAt(i);
if(b>='A'&&b<='Z')
{
buffer.append(String.valueOf(b).toLowerCase());
//先通过静态函数value()把b转换为字符串然后再调用toLowerCase()
}
else
{
buffer.append(String.valueOf(b).toUpperCase());
}
System.out.print(buffer.charAt(i));
}
System.out.println(buffer);
}
}