Loop counter initially assigned the value to the right of the equal sign (start). Only numerical variables are valid. The loop counter increases or decreases according to the variable Step until End is passed.
其初值为等号右边的值 (start) 的循环计数器。在此处仅数字变量有效。循环计数器会根据 step 变量的不同而递增或递减，直到达到 end 对应的值。