for循环超出了设置条件

I've set up for loop to make "i" to be incremented until "i < 10". After the for was finished I added an output statement after closing curly parentheses to show i value and it resulted to 10, whereas I thought that the max value could have been only 9. Could someone please explain what does cause "i" to go beyond it's maximum value of 9?I've set up for loop to make "i" to be incremen