As follows: Note, because in front of a function, according to use this function, so either in front of the statement, either on top before the functiondefinition.
如下：注意，因为前面的函数据要用到此函数，所以要么在前面声明，要么放在上面函数之前定义。
2
The syntax of a for statement is similar to a functiondefinition.